Hair Loss · Medication Guide
Finasteride in Thailand
What finasteride is, how well it works, its side effects, and how men in Bangkok get it legally. Reviewed by a licensed physician at a MOPH-registered men's health clinic.
- First results in 3–6 months
- Thai FDA registered · pharmacist dispensed
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Medically reviewed by Dr. Juthathinin Piwpong
Menscape Clinic
Last reviewed
11 July 2026
83%
Maintained or grew hair
at two years, in controlled trials
70%
Less scalp DHT
the hormone driving the condition
3–6
Months to first results
full assessment at 12 months
1,500+
Men in the trials
each followed for two years
Key takeaways
Finasteride 1 mg is an oral prescription medicine for male-pattern hair loss, and the most-studied oral treatment for it.
In controlled trials, 83% of men maintained or increased hair count at two years, versus 28% on placebo.
In Thailand it is classified as a dangerous drug (ยาอันตราย). It must come from a pharmacist or a doctor. Unlicensed online sellers are illegal and unsafe.
A doctor must assess whether it is suitable for you. Side effects are uncommon but real, and results take 3–6 months.
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What finasteride is & how it works
Finasteride is an oral prescription medicine used to treat male-pattern hair loss (androgenetic alopecia), the gradual, hormone-driven thinning at the temples and crown that affects most men at some point.
It works upstream of the problem. Male-pattern hair loss is driven by dihydrotestosterone (DHT), a by-product of testosterone that progressively shrinks genetically sensitive hair follicles. Finasteride blocks the enzyme that converts testosterone into DHT, lowering scalp DHT by roughly 70%. With less DHT, miniaturised follicles can stabilise and, in many men, recover thickness.
It treats the cause of the condition rather than stimulating growth directly. That is why it is often combined with topical minoxidil, and why it only works for as long as you take it.
Finasteride is one treatment option among several. Whether it is appropriate for you depends on your pattern of hair loss, age, health history and goals. That is what the doctor's assessment is for.
Testosterone → DHT
The enzyme 5α-reductase converts a small share of testosterone into DHT.
DHT shrinks follicles
In genetically sensitive men, DHT progressively miniaturises follicles at the hairline and crown.
Finasteride blocks the enzyme
One daily 1 mg tablet lowers scalp DHT by about 70%.¹
Follicles stabilise
Loss slows or stops; a majority of men regrow some hair over 12 months.²
02
Getting finasteride in Thailand
Thai FDA status
Registered with the Thai FDA and classified as a dangerous drug (ยาอันตราย). The original 1 mg product and several registered generics are available through licensed channels.³
Where it's legal to get
From a licensed pharmacy (first-class pharmacist) or prescribed by a doctor at a licensed clinic. Teleconsultation with licensed telepharmacy delivery is also legal.⁴
For expats & visitors
No Thai residency is required. Bring your medical history; a doctor can review continuity of treatment if you already take finasteride abroad.
Thai FDA warning. The regulator has repeatedly warned against buying prescription medicines from unlicensed online sellers. Counterfeit products are common, and nobody is accountable for what you receive.⁵
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Does it work? The evidence
Finasteride 1 mg is among the most-studied treatments in dermatology. In the pivotal randomised controlled trials (1,553 men, 18–41, followed for two years), 83% of men taking finasteride maintained or increased their hair count, compared with 28% of men on placebo. Photographic assessment rated 66% as visibly improved at two years.²
Long-term follow-up studies report the benefit is durable while treatment continues, including a 10-year Japanese study in which over 90% of men showed no further progression.⁶
Two things to know before you start. Results take time: shedding stabilises over 3 to 6 months and regrowth is assessed at 12. And the effect lasts only while you take it, because DHT returns to baseline within two weeks of stopping.
83%
Finasteride 1 mg
maintained or increased hair count at two years
28%
Placebo
same measure, no treatment
Randomised, placebo-controlled trials in men 18–41 with mild-to-moderate androgenetic alopecia. Individual results vary.
04
Side effects & who shouldn't take it
Uncommon side effects (1–4%)
Decreased libido (1.8% vs 1.3% on placebo), erectile difficulty (1.3% vs 0.7%), reduced ejaculate volume, and rare breast tenderness. In studies these resolved in most men who stopped, and in many who continued.²
Not suitable for
Women (pregnant women must not handle crushed or broken tablets), men under 18, men with hypersensitivity to finasteride, or significant liver disease.
Worth knowing
Mood changes have been reported, so tell your doctor about any history of mood disorder.⁷ Finasteride roughly halves PSA, so tell any doctor who tests your prostate that you take it.
Planning a family or donating blood?
Men actively trying to conceive may discuss timing with their doctor. Do not donate blood while taking it and for 1 month after. Annual follow-up is recommended.
05
Alternatives & combinations
Topical · often combined
Minoxidil
A topical solution or foam that stimulates follicles directly, frequently prescribed alongside finasteride for a stronger combined effect.
Oral · second-line
Dutasteride
A related enzyme blocker that lowers DHT further; a doctor may discuss it when finasteride response is insufficient.
Supportive care
Ketoconazole
A medicated anti-fungal shampoo with mild anti-DHT activity, used as an adjunct — not a standalone treatment.
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How prescription works at Menscape
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Book your free consultation today.
Online hair assessment
Five minutes on your phone: photos, health history, current medications. It is free and PDPA-protected.
Doctor consultation
A licensed Thai physician reviews your case by video call or in clinic at Asoke, confirms the diagnosis and decides whether medication is appropriate.
Prescription, if suitable
If the doctor approves, you receive a prescription. The medication is dispensed by a licensed pharmacy, for pickup or delivery.
Follow-up & monitoring
Progress photos and check-ins at 3 and 6 months. Dose and plan are adjusted with your doctor as results come in.
The doctor decides. Completing an assessment is not a purchase and does not guarantee a prescription. If finasteride is not right for you, your doctor will say so and discuss alternatives.
Medically reviewed by
Dr. Juthathinin Piwpong
Menscape Clinic, Bangkok
“Most men wait years longer than they should. Hair loss is a medical condition with well-studied treatments. The earlier we assess it, the more hair there is to save.”
- Reviewed
- 11 July 2026
- Next review
- January 2027
- Editorial standard
- Each guide is checked against the Thai FDA label and the primary literature, then reviewed by a licensed physician.
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Frequently asked questions
Can I buy finasteride over the counter in Thailand?
No. It is classified as a dangerous drug (ยาอันตราย): it must be dispensed by a licensed pharmacist or prescribed by a doctor. Anything sold without that oversight is illegal and a counterfeit risk.
How long until I see results?
Shedding typically stabilises within 3–6 months; regrowth is assessed at 12 months. Progress photos at 3 and 6 months help track the trend.
Do I have to take finasteride forever?
The effect lasts only while you take it. If you stop, DHT returns to baseline within about two weeks and gains fade over roughly 12 months.
How common are the sexual side effects, really?
In the pivotal trials, decreased libido affected 1.8% of men (vs 1.3% on placebo) and erectile difficulty 1.3% (vs 0.7%). Most cases resolved on stopping, and many while continuing.
Does finasteride affect fertility or planning a family?
Finasteride is not for women, and pregnant women must not handle crushed or broken tablets. Men actively trying to conceive should discuss timing with their doctor.
Is a teleconsultation enough, or do I need to visit the clinic?
For most hair-loss cases a teleconsultation is sufficient and legal in Thailand. Your doctor will ask you to come in to the clinic at Asoke if an in-person exam is needed.
What's the difference between finasteride and dutasteride?
Dutasteride blocks both forms of the 5α-reductase enzyme and lowers DHT further. Finasteride 1 mg remains the first-line, most-studied option; a doctor may discuss dutasteride if your response is insufficient.
I already take finasteride from abroad — can I continue it in Thailand?
Yes. You can usually continue taking finasteride in Thailand. If needed, a local doctor can review your treatment and provide a prescription.
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References
1. U.S. FDA. Propecia® (finasteride) prescribing information. Merck & Co. Accessed July 2026.
2. Kaufman KD, et al. Finasteride in the treatment of men with androgenetic alopecia. J Am Acad Dermatol. 1998;39(4):578-589.
3. Thai Food and Drug Administration — drug registration database, ndi.fda.moph.go.th. Accessed July 2026.
4. Pharmacy Council of Thailand, Notification No. 56/2563 on telepharmacy standards.
5. Thai FDA consumer warnings on purchasing medicines from unlicensed online sellers, oryor.com.
6. Yanagisawa M, et al. Long-term (10-year) study of finasteride 1 mg in Japanese men. Clin Res Trials. 2019.
7. European Medicines Agency PRAC review of finasteride. 2024–2025.
This guide is educational information, not medical advice. Finasteride is a prescription medicine that must be prescribed and monitored by a licensed physician.
This guide is part of the Menscape hair-loss library
Explore the condition hubWorried about hair loss? Ask a doctor, not a forum.
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