Permethrin Topical: What It Treats and How to Use It

Permethrin topical is a medicine used to treat lice and scabies. It kills the insects or mites by attacking their nervous system, so it works fast when used the right way. You’ll most often see it as a 1% lotion or a 5% cream — 1% for head lice and 5% for scabies in many places. Which strength you need depends on the condition your healthcare provider diagnoses.

How to apply permethrin safely

Always follow the label or your doctor’s instructions. For head lice, apply the 1% lotion to dry hair, leave it on for the time specified (usually 10 minutes to 8 hours depending on the product), then rinse. For scabies, the 5% cream is usually applied from the neck down and left on overnight (about 8–14 hours) before washing off. Wash your hands after applying and avoid getting it in your eyes, mouth, or open wounds.

If you’re treating a child, use the exact dose and contact time recommended for their age. Do not use products meant for animal use. If you need to treat bedding and clothing, wash them in hot water or seal them in plastic bags for a few days to prevent reinfestation.

Side effects, warnings, and when to call a doctor

Common side effects are mild: burning, stinging, redness, or itching where the medicine is applied. Those often get better after the first day. Rarely, people can have a severe allergic reaction — trouble breathing, swelling, or a rash that spreads. Stop use and seek emergency care if that happens.

Tell your provider if you’re pregnant, breastfeeding, or have a lot of broken skin. Permethrin is often allowed in pregnancy when benefits outweigh risks, but check with your clinician first. Avoid using multiple topical insecticides together; mixing treatments can increase irritation without helping the condition.

Permethrin usually doesn’t interact with oral medicines because it’s applied to the skin and not well absorbed. Still, mention any topical creams or strong medicated soaps you use — these can change how your skin reacts.

For lice, a second treatment after 7–10 days is commonly recommended to catch newly hatched eggs. For scabies, one application of 5% cream is sometimes enough, but a repeat treatment after one week may be advised if symptoms persist. If itching continues more than 2–4 weeks after treatment, see your healthcare provider — ongoing itching can come from skin inflammation, not a live infestation.

Buy permethrin from a pharmacy you trust. In many countries the 5% cream for scabies requires a prescription while some 1% lice lotions are available over the counter. Keep it out of reach of children, store at room temperature, and don’t freeze.

If you want a quick checklist: use the right strength, follow timing instructions exactly, treat close contacts or household items as advised, watch for signs of allergy, and talk to your doctor if symptoms don’t improve. That approach gets rid of the pests fast and keeps your skin safe.