How to apply permethrin to clothing
Even, long-lasting coverage takes about 30 minutes and six steps. Here's exactly how we treat our field gear each season — and the mistakes that waste half the bottle.
Treating clothing with permethrin is genuinely easy — but a few details separate a treatment that lasts six weeks from one that washes out early or leaves gaps ticks walk right through. Use a 0.5% permethrin clothing spray (the standard concentration; Sawyer and Ranger Ready both make one) and follow these steps.
Before you start: permethrin is for fabric only, and it's toxic to cats while wet. Work outdoors, keep cats away, and let everything dry fully before it comes back inside. Full detail: permethrin and cats →
The six steps
Work outdoors
Hang the garment on a hanger outside or in a ventilated garage, away from pets, food surfaces, and open water (permethrin is toxic to fish before it dries).
Spray to slightly damp
Hold the bottle 6–8 inches away and spray in slow, overlapping passes until the fabric is evenly damp — not soaked and dripping. Roughly 30 seconds per side of a shirt or pair of pants.
Prioritize the lower body
Ticks climb up from grass and leaf litter, so they hit your socks, pant legs, cuffs, and lower shirt first. Give those zones the most thorough coverage — that's where the treatment earns its keep.
Treat both sides
Turn the garment over and repeat so both faces of the fabric are covered. Don't forget the inside of cuffs and the back of pant legs.
Dry completely
Let it air-dry 2–4 hours until bone dry before wearing or storing. This is the step that makes it cat-safe and locks the treatment into the fibers. Don't machine-dry wet-treated clothing indoors.
Label and track
Note the date somewhere — phone reminder, tag, or a note in your gear bin. The treatment holds for about 6 weeks or 6 washes; re-treat when either passes.
Mistakes that waste the bottle
Under-spraying to save product. A light misting doesn't deposit enough to be reliably lethal to ticks. Damp-to-the-touch is the target. Treating only the outside. Both faces matter. Skipping socks. Socks and lower legs are the highest-value real estate and the most commonly missed. Washing hot. Hot water and heavy detergent strip the treatment fast — wash treated clothing cold and gently, and line-dry when you can.
How long will it protect?
A DIY treatment lasts about six weeks or six washes; factory pre-treated garments last far longer. To estimate exactly when your treated clothing — and your skin repellent — are due for a refresh:
Free tool Repellent duration calculator → Protection time and re-treatment timing for permethrin, picaridin, DEET and more.Part of our complete permethrin field guide. For the skin layer, see our tested repellent picks.