What Is Dutasteride, and Is It Approved in Japan?
Dutasteride is an oral medicine that blocks 5-alpha reductase. This enzyme converts testosterone into dihydrotestosterone (DHT), the hormone most closely linked to male pattern hair loss, also called androgenetic alopecia or AGA. Dutasteride blocks both the type I and type II forms of the enzyme. Finasteride mainly blocks type II.
Yes, dutasteride is approved in Japan. It is sold under two different brand names for two different conditions:
- Zagallo (ザガーロ) was approved on 28 September 2015 for male pattern hair loss in men. The Japanese label dose is 0.1 mg once daily, which can be raised to 0.5 mg once daily if needed.
- Avolve (アボルブ) 0.5 mg has been used since 2009 for benign prostatic hyperplasia (BPH), a non-cancerous enlargement of the prostate.
Generic versions approved for hair loss are also available. The first generic, Dutasteride Capsules ZA, was approved on 5 October 2020 and launched on 13 October 2020. In Japan, dutasteride is classed as a prescription-only medicine (処方箋医薬品) and a potent drug (劇薬).
How Dutasteride Works and What Results to Expect
DHT gradually shrinks hair follicles in genetically susceptible areas. Over time, they produce thinner and shorter hairs. Lowering DHT slows this process and, in some men, allows partial regrowth.
What the evidence shows
The Japanese Dermatological Association’s guideline on male and female pattern hair loss (2017 edition) gives oral dutasteride its highest recommendation grade, A, for male pattern hair loss. It also says dutasteride should not be used for female pattern hair loss (grade D).
The guideline summarises an international randomised trial of 917 men that included participants from Japan (Gubelin Harcha et al., 2014). After 6 months, dutasteride 0.5 mg daily outperformed finasteride 1 mg daily on total hair count and hair diameter. However, there was no significant difference in the number of thick terminal hairs (60 μm or wider). The expert-panel photo scores favoured dutasteride by only 0.14 points at the crown and 0.24 points at the front on a 7-point scale. The guideline concludes that the difference between the two drugs needs further study.
A 52-week study of 120 Japanese men taking 0.5 mg daily reported increases in non-vellus hairs (hairs 30 μm or wider) and terminal hairs. Photo assessments at weeks 26 and 52 showed significant improvement from baseline (Tsunemi et al., 2016).
Realistic expectations
The Japanese Zagallo label states that some improvement may appear within about 12 weeks, but results should be judged after 6 months. If there is no improvement after 6 months or more, treatment should be stopped. The guideline also notes that the trials it reviewed did not study effects beyond one year or what happens to hair after stopping.
Real Patient AGA Treatment Results — Before & After
The following are actual AGA (androgenetic alopecia) treatment results from patients at Kojimachi Dermatology & Plastic Surgery Clinic and its sister clinic BIOTOPE CLINIC (Shirokanedai, Minato-ku, Tokyo), both directed by Dr. Jun Karibe. Photos are shared with patient permission. Individual results vary depending on age, hair loss stage, adherence to medication, and treatment plan. Tap each case to view the full treatment disclosure required by the Japanese Medical Advertising Guidelines.
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Case 1 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 2 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 3 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 4 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 5 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 6 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 7 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 8 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 9 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 10 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 11 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 12 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 13 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 14 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
×
Case 15 — Treatment disclosure
Individual results vary. The information below is provided per the Japanese Medical Advertising Guidelines.
- Treatment category
- AGA (androgenetic alopecia) treatment — oral 5-alpha-reductase inhibitors (finasteride, dutasteride), topical or oral minoxidil, and optional regenerative scalp injection therapy.
- How it works
- Finasteride / dutasteride block DHT, the hormone that drives follicular miniaturization. Minoxidil prolongs the growth (anagen) phase and increases scalp blood flow. Stem-cell culture supernatant injections stimulate follicular regeneration. Visible improvement is typically observed after 3–6 months of continuous use.
- Number of sessions / duration
- Oral medications: daily use, results assessed at 3, 6, and 12 months.
Injection courses: typically 5 sessions.
Continued use is generally required to maintain results. - Main side effects
-
Finasteride / dutasteride: sexual dysfunction (decreased libido, erectile dysfunction, ejaculatory disorder), liver dysfunction, mood changes; dutasteride may also cause gastrointestinal symptoms.
Minoxidil: scalp irritation, itching, unwanted body hair; oral minoxidil may cause palpitations, dizziness, and lower-limb edema. Initial shedding may occur in the first 1–2 months.
Injection therapy: in rare cases, swelling, warmth, pain, or allergic reactions may occur; these typically subside over time. - Precautions & contraindications
- Finasteride and dutasteride must not be used by women — especially those pregnant, potentially pregnant, or breastfeeding — even physical contact with crushed or broken tablets should be avoided. Not for use in children. Patients with hepatic dysfunction, active prostate cancer, or a history of hypersensitivity should not use these medications. Oral minoxidil requires cardiovascular assessment before starting.
- Fees (Kojimachi Clinic / BIOTOPE CLINIC, tax included)
-
Oral medications (per box):
• Finasteride, 28 tablets: ¥4,800
• Zagallo (dutasteride), 30 capsules: ¥9,000
• Minoxidil (in-clinic formulation), 28 tablets: ¥8,800
Regenerative injection therapy (stem-cell culture supernatant, whole scalp):
• Single session: ¥80,000
• 5-session course: ¥300,000
Overall fee range: ¥80,000–¥300,000 for injection therapy. Oral medications add ¥4,800–¥9,000 per box. The exact plan and fee for each patient are confirmed at consultation. - Insurance
- Not covered by Japanese public health insurance. AGA treatment is an elective self-pay treatment. Prices may change — please confirm at consultation.
Legal Ways for Expats to Get Dutasteride in Japan
Travellers and residents usually have three options. They differ a lot in legal limits, safety checks and medical supervision.
| Route | What is required | Key limits and risks |
|---|---|---|
| Prescription from a doctor in Japan | A consultation with a doctor practising in Japan | Self-pay when prescribed for hair loss. The medicine goes through Japan's regulated supply chain. |
| Bringing your own supply when entering Japan | Medicine for your own personal use | Up to a 1-month supply of a prescription drug without Import Confirmation. More than that requires Import Confirmation (Yunyu Kakunin-sho) issued before you leave home. |
| Personal import by post from overseas | The same quantity rules as above | Quality is not checked by Japanese authorities. Health damage is not covered by Japan's drug side-effect relief system. You may not sell or give the medicine to anyone else. |
Option 1: A prescription from a doctor in Japan
This is the most straightforward option for anyone staying longer than a short trip. You can bring your current prescription or medication packaging to the consultation. This helps the doctor understand your history, dose and any side effects. The doctor then decides whether dutasteride suits you under Japanese labelling.
Option 2: Bringing your own supply
According to Japan's Ministry of Health, Labour and Welfare (MHLW), you can bring up to a 1-month supply of a prescription drug for personal use without Import Confirmation. If you need more, apply for Import Confirmation and receive it before you leave home. Then show it at customs when you arrive.
Option 3: Personal import by post
The same quantity limits apply to personal import. Japanese prefectural health authorities warn that personally imported medicines may be counterfeit, mislabelled or made in unhygienic conditions. They also note that health damage from personally imported medicines is not covered by Japan's relief system. Japan Customs guidance states that personally imported medicines are for your own use only and must not be sold or given to others.
Where to get a dutasteride prescription in Tokyo
Within our clinic group, both BIOTOPE CLINIC (Shirokanedai, Minato-ku) and Kojimachi Dermatology & Plastic Surgery Clinic (Ichigaya, Chiyoda-ku) offer English-language consultation with Dr. Jun Karibe's team. Dutasteride for male pattern hair loss is handled at BIOTOPE CLINIC in Shirokanedai, which provides men's health and cosmetic dermatology care. Bookings and enquiries in English: LINE or WhatsApp.
BIOTOPE CLINIC's hair-loss menu also includes finasteride and minoxidil. Feel free to ask Dr. Karibe during a consultation whether one of these, alone or combined, fits your situation better.
What People Often Get Wrong
Misconception 1: "Dutasteride is covered by Japanese health insurance"
Not when it is prescribed for hair loss. The Zagallo label states that it is not covered by health insurance (薬価基準未収載). Avolve, the BPH product, is prescribed for prostate enlargement. Its label states that insurance does not apply when it is prescribed for male pattern hair loss.
Misconception 2: "Only the person taking it needs to be careful"
Dutasteride is contraindicated (must not be used) in women and children. In animal studies it feminised the external genitals of male foetuses, and it can be absorbed through the skin. The label advises that anyone who touches medicine leaking from a capsule should wash immediately with soap and water. This matters if you live with a partner who is or may become pregnant.
Cost in Tokyo
When prescribed for male pattern hair loss, dutasteride is self-pay in Japan. Your total cost usually depends on:
- The consultation fee, both initial and follow-up
- Brand-name Zagallo or an approved generic
- The prescribed dose (0.1 mg or 0.5 mg) and how many months are supplied at once
- Any blood tests your doctor recommends
Please see the clinic's official price page or contact us for a current quote. For an accurate quote, please book a consultation.
Have a question about this treatment?
Message us on LINE or WhatsApp — our English-speaking team usually replies the same day.
Who Is a Good Candidate, and What to Expect
Who may be suitable
- Adult men diagnosed with male pattern hair loss
- Men willing to take a daily medicine for at least 6 months before judging results
- Men already taking dutasteride abroad who want to continue under a doctor in Japan
Who should not take it
- Women and children (contraindicated)
- Anyone with a history of hypersensitivity to dutasteride or other 5-alpha reductase inhibitors
- People with severe liver impairment
The label also notes that safety and effectiveness have not been established in people under 20.
Side effects to discuss with your doctor
In the clinical trials for Zagallo's Japanese approval, adverse reactions occurred in 17.1% of participants. The most common were erectile dysfunction (4.3%), decreased libido (3.9%) and reduced semen volume (1.3%). In the 52-week Japanese study, rates were higher: decreased libido 8.3%, erectile dysfunction 11.7% and ejaculation disorder 5.0%. The guideline therefore stresses full explanation and informed consent before starting.
Practical points during treatment
- PSA tests: Dutasteride lowers PSA, the blood marker used in prostate cancer screening. The guideline advises doubling the measured PSA value as a guide. The label recommends using the PSA value taken 6 months after starting treatment as the new baseline.
- Blood donation: The Japanese Red Cross does not accept blood donations until 6 months after you stop dutasteride (Zagallo or Avolve). For finasteride, the wait is 1 month.
- Storage: Keep capsules in their original blister packs, away from light and moisture.
Frequently Asked Questions
- Q. Can a Japanese pharmacy fill my prescription from home?
- Dutasteride is a prescription-only medicine in Japan, so plan to see a doctor practising in Japan to get it here. Bring your current prescription or packaging to the consultation. This helps the doctor review your dose and history.
- Q. How much dutasteride can I bring when I travel to Japan?
- According to the MHLW, you can bring up to a 1-month supply of a prescription drug for personal use without Import Confirmation. For more, you need Import Confirmation (Yunyu Kakunin-sho) issued before you leave home.
- Q. Is dutasteride stronger than finasteride?
- In a trial of 917 men, dutasteride 0.5 mg outperformed finasteride 1 mg on total hair count and hair diameter at 6 months. The difference in terminal hairs was not significant, and the photo-score differences were small. Japan's 2017 guideline says the gap between the two drugs needs further study.
- Q. Can my partner handle my capsules?
- Women, especially those who are or may become pregnant, and children should not touch leaking capsules, because dutasteride can be absorbed through the skin. If contact happens, the label advises washing immediately with soap and water.
Have a question about this treatment?
Message us on LINE or WhatsApp — our English-speaking team usually replies the same day.
Summary
Dutasteride is approved in Japan. Zagallo has been approved for male pattern hair loss since 2015, and generic versions since 2020. When prescribed for hair loss, it is self-pay. For expats, the most reliable route is a consultation with a doctor in Japan. You can bring up to a 1-month supply for personal use without Import Confirmation, but personally imported medicine is not covered by Japan's relief system if something goes wrong.
Before starting, it helps to understand the side effects, the effect on PSA tests, the 6-month blood donation rule and the precautions for women and children.
If you have questions about getting dutasteride in Japan, both BIOTOPE CLINIC (Shirokanedai, Minato-ku) and Kojimachi Dermatology & Plastic Surgery Clinic (Ichigaya, Chiyoda-ku) offer English-language consultation with Dr. Karibe and his team. Dutasteride for male pattern hair loss is primarily handled at BIOTOPE CLINIC in Shirokanedai. English enquiries: LINE or WhatsApp.
24/7 Consultation & Booking
Book a Consultation or Treatment
Our English-speaking team responds via LINE or WhatsApp — usually the same day.
References
- Manabe M, Tsuboi R, Itami S, et al. Guidelines for the Diagnosis and Treatment of Male-Pattern and Female-Pattern Hair Loss, 2017 Version. The Japanese Journal of Dermatology (Japanese Dermatological Association). 2017;127(13):2763–2777.
- Gubelin Harcha W, Barboza Martínez J, Tsai TF, et al. A randomized, active- and placebo-controlled study of the efficacy and safety of different doses of dutasteride versus placebo and finasteride in the treatment of male subjects with androgenetic alopecia. Journal of the American Academy of Dermatology. 2014;70:489–498.
- Tsunemi Y, Irisawa R, Yoshiie H, et al. Long-term safety and efficacy of dutasteride in the treatment of male patients with androgenetic alopecia. Journal of Dermatology. 2016;43:1051–1058.
- GlaxoSmithKline K.K. Zagallo Capsules 0.1 mg / 0.5 mg, Japanese package insert (revised August 2025).
- Ministry of Health, Labour and Welfare, Japan. Information for those who are bringing medicines for personal use into Japan.
Related Articles
You may also find these articles useful.
- AGA vs Finasteride & Minoxidil: Tokyo Regenerative Care
- Hair Loss Treatment Tokyo: AGA Options for Expats
- English-Speaking Dermatologist Tokyo: Hair Loss & AGA
- Hair Mesotherapy Tokyo: Manual vs Hydro-Injector AGA
- How to Access Medical Care in Japan as a Foreign Visitor: A Practical Guide
SUPERVISED BY
Dr. Jun Karibe
MD
Director
Education & Career
Juntendo University School of Medicine
Department of Plastic Surgery, University of Tokyo Hospital
Assistant Professor, Plastic & Cosmetic Surgery, Saitama Medical University
Assistant Professor & Chief Resident, Yamanashi University Hospital
2019: Founded Kojimachi Dermatology & Plastic Surgery Clinic (Ichigaya, Tokyo)
2021: Founded BIOTOPE CLINIC Shirokanedai (Minato-ku, Tokyo)
Certifications
Board-certified Plastic Surgeon — Japan Society of Plastic and Reconstructive Surgery
Specialist — Japan Society of Anti-Aging Medicine
Certified Industrial Physician — Japan Medical Association
Allergan VST-certified Injector (Botox & Hyaluronic Acid)
Awards
Best Presentation Award — Dept. of Plastic Surgery, University of Tokyo (2016)
Excellence Award — Japan Society of Plastic and Reconstructive Surgery (2018)
Featured Presentation — ASPS Annual Scientific Meeting, USA (2018)
Instagram
MEDICAL REVIEW
Jun Karibe, MD — Board-certified Plastic Surgeon — Japan Society of Plastic and Reconstructive Surgery
Medical Director, BIOTOPE CLINIC
Last medically reviewed: 2026-09-11
