Terbinafine (Lamisil) for Fungal and Genital Infections

STI Treatments

Terbinafine (Lamisil) for Fungal and Genital Infections

Terbinafine (brand name Lamisil) is an antifungal medication used to treat fungal skin infections, including jock itch (tinea cruris), ringworm, and athlete’s foot. It’s not specifically an STI treatment, but genital fungal infections are common and sometimes confused with STIs.

If you’ve been prescribed terbinafine for a groin or genital infection, here’s how it works, the correct dosage, and what to expect.

What Does Terbinafine Treat?

Terbinafine does NOT treat candida (thrush), bacterial infections, or any STI. For genital thrush, use fluconazole or Gyno-Daktarin.

How Does Terbinafine Work?

Terbinafine kills fungi by inhibiting an enzyme (squalene epoxidase) needed to build fungal cell membranes. Without this enzyme, the fungal cells die. It’s effective against dermatophyte fungi (the organisms causing ringworm, jock itch, and athlete’s foot).

How to Use Terbinafine

Cream (Lamisil AT)

• Apply a thin layer to the affected area once or twice daily
• Wash and dry the area before applying
• Continue for 1-2 weeks even if symptoms improve earlier
• Available over the counter at pharmacies

Tablets (250mg)

• Take one 250mg tablet once daily with water
• Can be taken with or without food
• Duration depends on the infection (2-12 weeks)
• Prescription-only

Side Effects

Cream

Mild stinging, redness, or irritation at the application site. Allergic reactions are rare.

Tablets

• Nausea, diarrhoea, stomach pain (common)
• Headache
• Loss of taste or altered taste (uncommon but well-known, usually temporary)
• Rash
• Liver problems (rare but serious — report jaundice, dark urine, or persistent nausea)

Your doctor may check liver function before and during a long course of oral terbinafine.

Where to Get Terbinafine

• Cream: Over the counter at pharmacies (Lamisil AT or generic)
• Tablets: Prescription from GP or online prescriber

Read more: What is candida? | Genital infections | Lotriderm cream

Frequently Asked Questions

Is terbinafine used for STIs?

No. Terbinafine treats dermatophyte fungal infections (ringworm, jock itch, athlete’s foot). It does not treat chlamydia, gonorrhoea, herpes, or any STI.

Can I use terbinafine cream on my genitals?

Terbinafine cream can be used on the groin area for jock itch. It should not be applied to the vulva, vagina, or penis head. For candida infections in these areas, use clotrimazole or miconazole-based products.

How quickly does terbinafine work?

Cream: symptom relief within a few days, infection cleared in 1-2 weeks. Tablets: may take 2-6 weeks for skin infections and up to 12 weeks for nail infections. Nail infections may take months after treatment finishes for the healthy nail to fully grow out.

Related reading

• Using Antibiotics to Prevent STIs: DoxyPEP Explained
• Azithromycin: Uses in Sexual Health
• Best Antibiotics for STIs: A Practical Guide
• Ciprofloxacin for STIs: Uses, Dosage, and Side Effects
• Clindamycin: Uses in Sexual Health

Sources

• NHS — Sexual health conditions
• BASHH — UK clinical guidelines for STI management
• British HIV Association (BHIVA) — HIV treatment guidelines
• Terrence Higgins Trust — sexual health information
• UK Health Security Agency — STI surveillance data

Steve Page

Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.