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Dutasteride in Japan: Hair-Loss Products, Prices and Prescription Checks
This guide to Dutasteride in Japan covers AGA treatment, differences between products and safety. It separates medicine-specific information from the product and prescription checks needed for an individual consultation.
This page explains how Dutasteride works, its directions, limitations and safety. For prices and individual prescriptions, see SWIFT’s relevant care information.
Dutasteride is a 5α-reductase inhibitor for AGA in men. Distinguish its purpose from products with the same ingredient for benign prostatic hyperplasia. It is not used in women or children. Assess effects over continued treatment and check sexual and liver function effects.
Medical reviewer: Masashi Morita, MD
Dutasteride is a 5α-reductase inhibitor for AGA in men. Distinguish its purpose from products with the same ingredient for benign prostatic hyperplasia. It is not used in women or children. Assess effects over continued treatment and check sexual and liver function effects.
- Ingredient/class
- Dutasteride
- Eligible patients/indications
- Zagallo’s approved indication is androgenetic alopecia in men. Women, children and people with severe liver impairment are among those for whom it is contraindicated. The existence of products such as Avolve for benign prostatic hyperplasia does not justify repurposing them yourself for AGA.
- Assessing effects
- Improvement may be seen at 12 weeks, but effects are usually assessed after 6 months of continued use. The prescribing information calls for discontinuation if there is no improvement after at least 6 months. A doctor assesses the response and whether treatment should stop or continue.
- Clinic care
- Service information supported by public sources is identified in the article. Final prescribing decisions are made during consultation.
What the medicine is
It inhibits type 1 and type 2 5α-reductase, suppressing conversion of testosterone to DHT. It targets male pattern hair loss involving DHT; it is not effective for every type of alopecia.
Eligible patients and approved indications
Zagallo’s approved indication is androgenetic alopecia in men. Women, children and people with severe liver impairment are among those for whom it is contraindicated. The existence of products such as Avolve for benign prostatic hyperplasia does not justify repurposing them yourself for AGA.
Source: Medicine-specific primary documentation. The product used by the clinic is not assumed to be identical to the formulation in this documentation.
Treatment limitations and when diagnosis is needed
It does not increase hair immediately; progression and hair status are assessed over months. More medicine does not guarantee more growth. If it is ineffective, review the hair-loss diagnosis itself.
Formulations and basic directions
The approved AGA directions for adult men are 0.1 mg once daily, or 0.5 mg if needed. Swallow capsules without chewing and avoid touching leaked contents. The clinic’s combination tablet differs from single-ingredient Zagallo capsules; check ingredient amounts and prescribing instructions.
Source: Medicine-specific primary documentation. The product used by the clinic is not assumed to be identical to the formulation in this documentation.
Timing of response and decisions about continuation
Improvement may be seen at 12 weeks, but effects are usually assessed after 6 months of continued use. The prescribing information calls for discontinuation if there is no improvement after at least 6 months. A doctor assesses the response and whether treatment should stop or continue.
Side effects and symptoms to watch for
Reduced libido, reduced erectile function, changes in ejaculation and breast symptoms can occur. Watch for liver dysfunction and jaundice; disclose mental or physical changes such as depressed mood promptly.
Source: Medicine-specific primary documentation. The product used by the clinic is not assumed to be identical to the formulation in this documentation.
When to stop and seek medical attention
Jaundice, marked fatigue, reduced appetite or a breast lump require examination. For suspected hypersensitivity such as breathing difficulty or swelling of the face or throat, do not take additional doses; seek medical attention promptly.
Restrictions and interactions
Do not use it in women or children, with serious liver impairment or with hypersensitivity to 5α-reductase inhibitors. Check concurrent CYP3A4 inhibitors and other medicines affecting blood concentrations. It lowers PSA, so disclose use to the clinician performing a prostate assessment.
Source: Medicine-specific primary documentation. The product used by the clinic is not assumed to be identical to the formulation in this documentation.
Pregnancy, breastfeeding and patient precautions
Women and children must not touch medicine leaking from a capsule. If contact occurs, wash the area immediately with soap and water. Women must not take this medicine.
Additional care
Take photographs under consistent conditions and review progression and side effects as well as perceived hair growth. Do not add finasteride yourself; provide the medicine name for blood or prostate tests.
Storage and quality checks
The Japanese Zagallo prescribing information directs storage at room temperature in blister packaging to protect from light and moisture. Do not use broken or leaking capsules; contact the prescriber. Do not assume the clinic’s product or combination tablets are Japanese Zagallo; follow the actual storage label.
Differences from other medicines and treatments
Finasteride mainly inhibits type 2. Differences in action do not mean dutasteride is superior for everyone. Minoxidil has another mechanism; combinations also require an explanation that oral minoxidil is unapproved in Japan.
Dutasteride prices in Japan: what exactly are you comparing?
A search for dutasteride tablets or a 0.5 mg price can mix hair-loss products, prostate medicines and combination treatments. The ingredient and strength alone do not identify the indication or show that two products are interchangeable.
Before asking about a refill or changing from an overseas product, note its name, strength and ingredients. Check the actual product, pack quantity and total charges through SWIFT’s English care page and consultation. Do not assume that a Zagallo, Avolve or combination listing refers to the product the clinic will prescribe.
Discussing consultation and prescribing with SWIFT
SWIFT’s official information lists single-ingredient medicines and combinations containing minoxidil. Confirm each product’s approval status, ingredients, actual prescribed formulation, strength and current costs during consultation.
Frequently asked questions
For Dutasteride, is it the same as Zagallo?
Zagallo is a dutasteride brand for AGA. Combination tablets and prostate products are not necessarily the same.
For Dutasteride, can women take it?
Use in women is contraindicated. Do not share a medicine intended for men.
For Dutasteride, does it affect PSA testing?
It lowers PSA values, so always tell the clinician performing the test that you take it.
Can I use a dutasteride 0.5 mg price to compare treatment costs?
Check the intended use, actual formulation, quantity and fees as well as the strength. The linked English care page covers clinic arrangements; the medicine you receive and whether it is suitable require confirmation during consultation.
Medical supervision
Dr Masashi Morita (Board-certified specialist and supervising physician, Japanese Urological Association / Board-certified specialist, Japan Endocrine Society / Doctor of Medical Science).