Terbinafine: Uses, Cream vs Tablets, Side Effects & Liver Risk

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What is terbinafine and what does it treat?

This page explains, in plain English, what terbinafine treats, the real difference between the cream and the tablets, the side effects worth knowing about, why a liver check matters for the tablets, and exactly when you should see a GP instead of self-treating.

Why this matters

If you have a simple ringworm patch or athlete’s foot, an over-the-counter terbinafine cream often clears it within a couple of weeks. But if the problem is in a nail, on the scalp, spreading fast, or keeps coming back, cream alone usually will not fix it, and that is the point where a GP or online prescriber needs to step in. Knowing which situation you are in saves you weeks of treating the wrong thing.

What is terbinafine?

Terbinafine is an antifungal drug. It belongs to a group called the allylamines. You may also see it sold under the brand name Lamisil, and the cream is sold under several pharmacy own-brand and Lamisil AT names.

It is used specifically for infections caused by fungi (including dermatophytes and some yeasts). It does not treat bacterial infections or viral ones, so it will not help with most spots, boils or cold sores.

How does terbinafine work?

Fungi need a substance called ergosterol to build healthy cell membranes. Terbinafine blocks an enzyme called squalene epoxidase that the fungus uses to make ergosterol. Without it, a toxic substance (squalene) builds up inside the fungal cells and they die off. Because human cells do not rely on that same pathway in the same way, terbinafine targets the fungus while largely leaving your own skin cells alone.

In short: it kills the fungus rather than just slowing it down, which is part of why courses can be relatively short for skin infections.

What is terbinafine used for?

Terbinafine treats a range of fungal infections. The common ones include:

• Athlete’s foot (tinea pedis): itching, cracking and peeling between the toes and on the soles.
• Ringworm of the body (tinea corporis): a red or discoloured ring-shaped rash with a clearer centre.
• Jock itch (tinea cruris): a fungal rash in the groin and inner thighs.
• Fungal nail infections (onychomycosis): thickened, crumbly, discoloured toenails or fingernails. These almost always need the tablets.
• Scalp ringworm (tinea capitis): a fungal infection of the scalp and hair, which needs oral treatment and is more common in children, so should always be assessed by a GP.

Note that fungal infections of the skin are not the same as fungal acne (a yeast-driven rash of small uniform bumps). That is treated differently, often with antifungal washes or other agents rather than terbinafine tablets. If you are unsure which you have, see our guide on fungal acne.

Cream vs tablets: which form do you need?

This is the decision most people land on this page for. The short version: the cream is for skin, and the tablets are for nails, scalp and stubborn or widespread skin infections.

When the cream is the right choice

For a single patch of ringworm, a bout of jock itch, or athlete’s foot that is not severe, an over-the-counter terbinafine cream is usually the sensible first step. It is cheap, low-risk and often works fast. The BNF confirms that terbinafine 1% cream can be sold over the counter for people over 16 for athlete’s foot.

Typical pricing for OTC terbinafine 1% cream in the UK runs from about £3 to £8 for a small tube. As an example, Lamisil AT 1% Cream (15g) is around £6.75 to £7.49 on Amazon UK, while supermarket and pharmacy own-brand terbinafine 1% creams are often cheaper.

OTC terbinafine 1% creams (Amazon UK):

– Lamisil AT 1% Athlete’s Foot Cream, 15g — around £6.75 to £7.49, the original branded terbinafine 1% cream (4.6 stars, 7,000+ reviews).

– Lamisil AT 1% Spray — a spray format of the same 1% terbinafine, handy for larger areas.

– Lamisil Once (single-dose film-forming solution) — a one-application terbinafine treatment that forms a film over athlete’s foot.

– Or compare all options: terbinafine cream on Amazon UK.

Always read the label, and check the product contains terbinafine if you specifically want this drug. Many supermarket “athlete’s foot” creams use a different antifungal (such as clotrimazole or miconazole), which works differently.

When you need the tablets

You generally need the tablets when:

• the infection is in a nail (cream almost never penetrates a nail effectively),
• it is scalp ringworm,
• the skin infection is widespread, severe, or keeps returning after topical treatment, or
• the cream has been used correctly for the recommended time and the rash is not clearing.

Tablets are prescription only in the UK. You can get them through your GP, or through a regulated UK online pharmacy that runs an online consultation and, for the tablets, usually requires a liver function test. Online private prescription prices vary; on the live UK market they typically run from about £19.99 to £30 or more for a course of terbinafine 250mg tablets, depending on the pharmacy and course length (for example, around £19.99 at Prescription Doctor and £29.99 at Simple Online Pharmacy). These prescription tablets are not an over-the-counter purchase and are not sold through general retailers.

How to use terbinafine

Always follow the instructions on your specific product or from your pharmacist, prescriber or GP, as they can differ.

Cream, gel or spray: Wash and dry the affected area, then apply a thin layer over the rash and slightly beyond its edge, usually once or twice a day. Keep using it for the full recommended period even if the rash looks better, because stopping early is a common reason infections come back. According to the NHS, most skin infections improve within 1 to 2 weeks of starting treatment.

Tablets: These are typically taken once a day, with or without food, swallowed whole with a drink of water. The course length depends on the infection (short for skin, much longer for nails). Finishing the full course matters: with nails especially, the visible improvement often appears only after the course ends, because you are waiting for healthy nail to grow out.

If you miss a dose, take it when you remember unless it is nearly time for the next one. Do not double up to make up for a missed dose.

Side effects of terbinafine

Most people tolerate terbinafine well, and the cream in particular tends to cause only mild, local effects. As with any medicine, side effects are possible. This is a general summary, not a complete list: always read the patient information leaflet that comes with your product (available on the emc website) for the full detail.

Common with the cream: redness, itching, stinging, peeling or dryness where it is applied. These are usually mild.

Possible with the tablets: stomach upset, reduced appetite, headache, a rash, joint or muscle aches, and changes to taste or smell. Taste changes can be unpleasant and occasionally last a while, but they usually settle after stopping the medicine.

Less common but important: terbinafine tablets can, rarely, affect the liver. Signs to watch for include unusual tiredness, nausea, loss of appetite, yellowing of the skin or eyes (jaundice), dark urine or pale stools. Serious skin reactions are also rare but possible.

Seek urgent medical help if you have signs of a serious allergic reaction (swelling of the face, lips or throat, difficulty breathing, a widespread or blistering rash) or signs of a liver problem. Stop the medicine and get medical advice straight away.

Terbinafine and your liver: why checks matter

This is the single most important safety point about the tablets. Terbinafine is processed by the liver and, in rare cases, can cause liver injury, even in people with no known liver problem. Because of this, UK guidance (the NICE BNF) advises:

• Terbinafine tablets are not generally recommended for people with active or long-term (chronic) liver disease.
• A liver function test is done before starting the tablets, and then checked periodically, typically after about 4 to 6 weeks of treatment, with the medicine stopped if liver test results become abnormal.
• This is exactly why responsible UK online pharmacies ask for a liver function test before dispensing the tablets, rather than just selling them.

The cream does not carry this liver risk in the same way, because very little terbinafine is absorbed into the body from the skin.

Terbinafine and alcohol, pregnancy and other medicines

• Alcohol: Because terbinafine tablets are handled by the liver, heavy or daily drinking during treatment may add to the strain on the liver. If you take the tablets, it is sensible to limit alcohol and follow the advice in the leaflet or from your prescriber.
• Pregnancy and breastfeeding: Oral terbinafine is generally avoided in pregnancy and breastfeeding unless clearly needed. If you are pregnant, trying to conceive, or breastfeeding, tell your GP or prescriber before using it.
• Other medicines: Terbinafine can interact with several medicines by raising their levels in the body, including certain antidepressants (such as some tricyclics), some painkillers (such as codeine and tramadol), tamoxifen, and certain heart and diabetes medicines. Tell your prescriber about everything you take, including anything bought without a prescription. The NICE BNF lists the full interaction detail.

Do I need a prescription for terbinafine in the UK?

It depends on the form:

• Cream, gel or spray: Available over the counter from pharmacies for certain skin infections like athlete’s foot, ringworm and jock itch. No prescription needed, though a pharmacist may ask a few questions first. The 1% cream can be sold to people over 16.
• Tablets: Prescription only (POM). You get them from your GP, or from a regulated UK online pharmacy after an online consultation and, usually, a liver function test.

If you are going the online route, only use a pharmacy registered with the General Pharmaceutical Council. A legitimate service will ask health questions, request a liver test for the tablets, and have a prescriber review your case rather than simply selling on demand. For how to access dermatology care in the UK, including NHS and private routes, see our guide on how to see a dermatologist in the UK.

When to see a GP or dermatologist

Self-treating with an over-the-counter cream is reasonable for a mild, obvious skin fungal infection. See a GP, or ask a pharmacist for advice, if:

• the infection is in a nail, or on the scalp (these need the tablets and proper assessment),
• the rash is spreading, very itchy, painful, blistering or weeping,
• it has not improved after using a suitable cream correctly for the recommended time,
• it keeps coming back,
• you have diabetes, a weakened immune system, or poor circulation, where infections need closer attention,
• you are pregnant or breastfeeding, or
• you are not sure it is fungal at all. Several non-fungal rashes look similar, and treating the wrong thing wastes time.

A GP can confirm the diagnosis (sometimes with a simple skin or nail sample), prescribe tablets if needed, and refer to a dermatologist for stubborn or unusual cases. If you need to find the right route to care, our guide to seeing a dermatologist in the UK walks through NHS referral and going private.

Frequently asked questions

The bottom line

Terbinafine is a well-established, effective antifungal. For straightforward skin infections, the over-the-counter 1% cream is usually the right first move, and it is inexpensive. For nails, the scalp, or anything stubborn, widespread or recurring, you need the tablets, which are prescription only and require a liver check because of a rare but real liver risk. When in doubt about whether something is even fungal, get it looked at before you treat it.

This is general information, not medical advice. Always read the patient information leaflet, follow the advice of a pharmacist, GP or prescriber, and see a GP or dermatologist about your own skin.

Sources

• NHS: Terbinafine (a medicine to treat fungal skin infections)
• NHS: Ringworm, athlete’s foot and other fungal infections
• British Association of Dermatologists (BAD): patient information leaflets
• DermNet: Terbinafine
• NICE BNF: Terbinafine (including liver-function monitoring, interactions and cautions)
• electronic Medicines Compendium (emc): Terbinafine 250mg Tablet Patient Information Leaflet