Fungal Infections · Medication Guide
Terbinafine in Thailand
What terbinafine treats, how well it works on skin and nails, its side effects, and how men in Bangkok get it safely. Reviewed by a licensed physician at a MOPH-registered men's health clinic.
- Cream for skin · tablets for nails
- Topical from pharmacists · oral by prescription
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Medically reviewed by Dr. Noppon Arunkajohnsak (Win)
Menscape Clinic
Last reviewed
11 July 2026
250 mg
Standard oral dose
one tablet once daily for adults
12 wk
Toenail oral course
about 6 weeks for fingernails
~70%
Fungus cleared, toenails
mycological cure on the drug label
9–12
Months for nails to clear
the healthy nail has to grow out
Key takeaways
Terbinafine is an antifungal for dermatophyte infections: athlete's foot, jock itch, ringworm and fungal nails. A cream treats the skin; tablets are used for nails.
For toenail fungus, a 12-week oral course clears the fungus on testing in roughly 70% of people, but the nail only looks normal months later as it grows out.
In Thailand the 1% cream is a pharmacy medicine you can get from a pharmacist; oral terbinafine is prescription-only because it needs a diagnosis and a liver check.
Oral terbinafine calls for a baseline liver test and is not suitable with active liver disease. A doctor decides whether it is right for you.
01
What terbinafine is & how it works
Terbinafine is an antifungal medicine used to treat infections caused by dermatophytes, the group of fungi behind athlete's foot (tinea pedis), jock itch (tinea cruris), ringworm (tinea corporis) and fungal nails (onychomycosis). Thailand's heat and humidity keep skin and feet damp, which is exactly what these fungi thrive on, so they are among the most common skin complaints men bring to the clinic.
It works by starving the fungus. Fungal cell membranes depend on a fat called ergosterol. Terbinafine blocks squalene epoxidase, an enzyme early in the pathway that makes ergosterol. Ergosterol runs out and a precursor called squalene builds up to toxic levels, which kills the fungus rather than merely stopping it from growing.
It comes in two forms. A 1% cream treats infections of the skin. Oral tablets are used when the infection is in the nails, or too widespread for a cream, because the drug concentrates in skin, nails and hair and keeps working for weeks after the last dose.
Which form is right depends on where the infection is and how sure the diagnosis is. Nail fungus in particular is often confused with other nail problems, so a doctor's assessment, sometimes with a nail or skin sample, matters before starting a long oral course.
Fungus needs ergosterol
Dermatophytes build their cell membrane from ergosterol, much as our cells use cholesterol.
Terbinafine blocks the enzyme
It shuts down squalene epoxidase, early in the ergosterol pathway.¹
The fungal cell fails
Ergosterol runs out and squalene builds up to toxic levels inside the fungus.
Fungicidal, and it lingers
The fungus is killed, and terbinafine stays in skin and nails for weeks, so nails keep clearing after you stop.²
02
Getting terbinafine in Thailand
Thai FDA status
Both topical and oral terbinafine are registered with the Thai FDA. The 1% cream is a pharmacy medicine a pharmacist can hand over; oral tablets are prescription-controlled because of the diagnosis and liver monitoring they need. Sold in Thailand under brands such as Lamisil alongside registered generics.³
How to get it through Menscape
Menscape does not keep terbinafine on the shelf. The 1% cream can be provided on request for skin infections. Oral terbinafine is ordered for you individually after a doctor consultation and a baseline liver test. It is never dispensed same-day without that assessment.
Safety vs the grey market
Oral antifungals bought from unlicensed online sellers are a real risk: counterfeit tablets, wrong strengths, and no liver check before a drug that can rarely harm the liver. In humid Thailand demand is high and the grey market is active, so get oral courses through a clinic or pharmacy.⁴
Thai FDA warning. Prescription medicines from unlicensed online sellers are illegal and frequently counterfeit. Oral terbinafine should only be taken under medical supervision, with liver testing.⁴
03
Does it work? The evidence
Oral terbinafine is the first-line treatment for dermatophyte toenail infection and the most effective option in head-to-head antifungal trials.⁵ Per its prescribing information, a 12-week course clears the fungus on testing (mycological cure) in about 70% of people; a fully normal-looking nail is reached in around 38%, because the previously damaged nail still has to grow out. That regrowth takes 9–12 months, so nail results are judged long after the tablets finish.¹
For skin infections the picture is faster. The 1% cream clears most cases of athlete's foot within 1–2 weeks of treatment, and oral courses for jock itch or ringworm typically run 2–4 weeks. Two things to set expectations: nail results are slow, and reinfection is common in a hot climate unless footwear and moisture are managed.
~70%
Mycological cure
fungus cleared on testing, toenails
~38%
Complete cure
plus a fully normal-looking nail
Toenail onychomycosis, 12-week oral course, per the terbinafine prescribing information. Nail appearance improves over 9–12 months. Individual results vary.
04
Side effects & who shouldn't take it
Common, usually mild
With oral terbinafine: headache, digestive upset (diarrhoea, indigestion) and a temporary change in or loss of taste. Taste usually returns within weeks of stopping, though rarely it lasts longer. A skin rash can occur with either form.⁶
Serious but rare
Rare liver injury, including isolated cases of liver failure, is why oral courses need a baseline liver test and prompt review if you develop nausea, dark urine, yellowing or right-upper-tummy pain. Rare severe skin reactions (SJS/TEN, DRESS) and worsening of lupus have also been reported.⁶
Not suitable for
People with active or chronic liver disease, severe kidney impairment, or a known allergy to terbinafine should not take the oral form. Tell your doctor if you have lupus or a mood disorder. Discuss pregnancy or breastfeeding: the cream is generally preferred and oral courses are usually deferred.
Interactions to flag
Oral terbinafine can raise levels of some medicines handled by the CYP2D6 enzyme, including certain antidepressants (tricyclics, some SSRIs), some beta-blockers and antiarrhythmics. Bring a full list of what you take so the doctor can check for clashes.¹
05
Alternatives & combinations
Oral · alternative
Itraconazole
A broader azole antifungal used when terbinafine is unsuitable or the fungus is a non-dermatophyte. It carries more drug interactions and its own monitoring, and a doctor weighs it case by case.
Topical · first for skin
Antifungal creams & lacquers
The 1% cream, azole creams or a medicated nail lacquer treat skin infections and mild, early nail involvement, and are often the whole answer when the fungus has not reached deep into the nail.
Prevention · everyday
Moisture & footwear care
Keeping feet dry, rotating shoes, and being careful in shared showers matters as much as the drug in Thailand's humidity. Reinfection is the main reason treatment appears to 'fail'.
06
How prescription works at Menscape
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Book your consultation today.
Message us on WhatsApp or LINE
A few minutes on your phone: photos of the affected skin or nails, your symptoms, health history and current medicines. Free and PDPA-protected.
Doctor consultation
A licensed Thai physician reviews your case by video or in clinic at Asoke, confirms it is a fungal infection, sometimes with a nail or skin sample, and chooses topical or oral treatment.
Cream or prescription, if suitable
The 1% cream can be provided for skin infections. If an oral course is needed, the doctor arranges a baseline liver test first, then orders your tablets for pickup or delivery.
Follow-up & monitoring
Skin is reviewed after a couple of weeks; nail treatment is tracked over months, with repeat liver checks during longer oral courses.
The doctor decides. Starting a conversation is not a commitment and does not guarantee a prescription. If oral terbinafine is not right for you, your doctor will say so and discuss alternatives.
Medically reviewed by
Dr. Noppon Arunkajohnsak (Win)
Menscape Clinic, Bangkok
“Most nail-fungus 'failures' I see are either the wrong diagnosis or stopping too soon. Confirm it is a dermatophyte, check the liver before an oral course, and give the nail the months it needs to grow out.”
- 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.
07
Frequently asked questions
Can I buy terbinafine over the counter in Thailand?
The 1% cream, yes: it is a pharmacy medicine a pharmacist can hand over for athlete's foot or jock itch. Oral terbinafine tablets are prescription-only, because they need a proper diagnosis and a baseline liver check. Tablets sold online without that oversight are illegal and often counterfeit.
Do I need tablets, or is the cream enough?
Skin infections such as athlete's foot, jock itch and ringworm usually clear with the cream. Nail infections and widespread or stubborn cases generally need oral tablets, because a cream cannot reach fungus inside the nail. A doctor helps you decide.
How long until my toenail looks normal again?
The tablets are a 12-week course for toenails, but the nail only looks normal as it grows out, roughly 9–12 months. The fungus is often cleared on testing well before the nail appears healthy.
Is oral terbinafine bad for the liver?
Serious liver injury is rare but real, which is why a baseline liver test is done before an oral course. Stop and call the clinic if you develop nausea, dark urine or yellowing of the skin or eyes. People with active liver disease should not take the oral form.
Why does my taste change on terbinafine?
A temporary change in or loss of taste affects a small share of people on oral terbinafine. It usually returns within a few weeks of finishing the course, though rarely it lasts longer. Tell your doctor if it bothers you.
Why do I keep getting athlete's foot in Thailand?
The heat and humidity keep feet damp, which is ideal for dermatophytes, and reinfection from shared showers, pools and shoes is common. Treatment works better when you also keep feet dry, rotate footwear and treat both feet even if only one looks affected.
Can I drink alcohol while taking it?
Because terbinafine is processed by the liver and can rarely affect it, it is sensible to limit alcohol during an oral course, and to avoid heavy drinking. Ask your doctor about your own situation.
Can I continue the terbinafine I brought from home?
Yes. A local doctor can review your treatment and, if appropriate, continue it with the right monitoring. Bring your prescription and any recent liver-test results.
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References
1. U.S. FDA. Lamisil® (terbinafine hydrochloride) tablets prescribing information. Novartis. Accessed July 2026.
2. Darkes MJM, Scott LJ, Goa KL. Terbinafine: a review of its use in onychomycosis in adults. Am J Clin Dermatol. 2003;4(1):39-65.
3. Thai Food and Drug Administration (อย.). Drug registration database, ndi.fda.moph.go.th. Accessed July 2026.
4. Thai FDA (อย.) consumer warnings on purchasing medicines from unlicensed online sellers, oryor.com.
5. Evans EGV, Sigurgeirsson B. Double blind, randomised study of continuous terbinafine compared with intermittent itraconazole in treatment of toenail onychomycosis (L.I.O.N. study). BMJ. 1999;318(7190):1031-1035.
6. European Medicines Agency / MHRA safety information on oral terbinafine (hepatic and severe cutaneous reactions). Accessed July 2026.
7. Ameen M, et al. British Association of Dermatologists' guidelines for the management of onychomycosis. Br J Dermatol. 2014;171(5):937-958.
This guide is educational information, not medical advice. Oral terbinafine is a prescription medicine that must be prescribed and monitored by a licensed physician, including liver testing.
This guide is part of the Menscape infection library
Book a consultationNail or skin fungus that won't quit? Ask a doctor, not a forum.
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