From the Guidelines
Permethrin is a highly effective tick repellent and insecticide that should be used to treat clothing and gear, not applied directly to skin, to protect against tick bites and tick-borne diseases. For tick prevention, use a 0.5% permethrin solution specifically labeled for clothing and gear treatment. Apply it to clothing, shoes, socks, and outdoor gear by spraying until damp and allowing items to dry completely before wearing (typically 2-4 hours) 1. One application remains effective through multiple washings, generally lasting about 6 weeks or through 6 wash cycles. Permethrin works by both repelling ticks and killing them on contact with treated surfaces. It's particularly effective when combined with a DEET-based skin repellent for comprehensive protection.
Key Points to Consider
- Permethrin-treated or impregnated clothing can significantly reduce the number of tick bites when working outdoors 1.
- Permethrin is safe when used as directed but should never be applied directly to skin 1.
- This treatment is especially recommended for people who spend time in wooded areas, tall grass, or other tick habitats.
- For maximum protection, also perform regular tick checks after outdoor activities and use tick repellents containing DEET, IR3535, or picaridin when outdoors 1.
Application and Precautions
- Apply permethrin to outer clothing, such as shirts and pants, and not directly to skin 1.
- Allow clothing to completely dry before being worn.
- Pre-treated clothing is available and remains effective for multiple launderings.
- Always follow package label instructions for application and use.
From the FDA Drug Label
Permethrin, a pyrethroid, is active against a broad range of pests including lice, ticks, fleas, mites, and other arthropods.
- Permethrin is active against ticks.
- The drug label directly supports the use of permethrin as a tick repellant 2.
From the Research
Permethrin as a Tick Repellent
- Permethrin is a synthetic pyrethroid with acaricide and repellent properties, used for clothing impregnation to prevent tick bites 3, 4.
- It is considered an effective clothing repellent, with studies showing a significant reduction in tick bites when used 4, 5, 6.
- Permethrin-impregnated clothing has been shown to retain insecticidal activity for over 70 washes, making it a long-lasting solution for tick bite prevention 5.
Efficacy of Permethrin-Impregnated Clothing
- A pilot study found that long-lasting permethrin-impregnated clothing reduced tick bites by 93% among outdoor workers 5.
- A randomized control trial among outdoor workers in an endemic Lyme disease setting found that factory-impregnated permethrin clothing reduced tick bites by 58% over a 2-year period 6.
- Another study found that permethrin is by far the most effective clothing repellent, and that using DEET plus a permethrin-containing clothing repellent offers the best overall protection against tick bites 4.
Comparison with Other Repellents
- Permethrin is often compared to other repellents such as DEET, picaridin, and IR3535, which are applied to the skin or clothing 3, 7.
- While these repellents are effective, permethrin-impregnated clothing has been shown to provide long-lasting protection against tick bites, making it a useful addition to other preventive measures 5, 6.