The night routine
Four steps. Three of them are free.
This is the routine the Night Cap is built around. It follows the drying advice minoxidil manufacturers already give2, and it works whether or not you ever buy a cap.
- Apply after dinner, not at bedtimeTie it to a habit instead of a clock. Moving your application earlier is the single biggest fix on this page.
- Wait until it's fully dryAt least 2 hours for liquid, 4 is better. For foam, wait until it is completely dry. Dryness check: touch the back of your hand to your scalp. If it feels cool or tacky, it isn't dry yet.
- Wash your hands with soapResidue on your hands ends up on everything you touch next. That includes your pet.
- Cap on. Lights out.The Night Cap is made for minoxidil: it sits loosely over dry hair and puts a barrier layer between your hair and your pillow. Take it off in the morning. Wash it once a week.
- Never on wet hair
- Never all day
- Never pulled tight
Why loose, dry and night-only
In 2025 a medical journal described a 28-year-old woman who used 5% minoxidil twice a day, wore a wig all day, and a tight cap all night. Her scalp was covered almost around the clock. More of the drug reached her bloodstream than it should have. She grew unwanted hair on her face, arms and legs, and woke up with swelling around her eyes. It cleared after she stopped.4
That is the opposite of how the Night Cap is used: loose, over fully dry hair, at night only. If you already wear a wig or a tight hat during the day, talk to your doctor before adding a night cap.
If you live with pets
The cap covers one route, your pillow. The veterinary literature describes others1: a pet licking your skin or hair, a spill, a bottle left within reach, an applicator in the trash. Keep the bottle shut away, wipe up spills straight away, wash your hands after every application, and don't let pets lick treated skin or hair. If you think your pet has had contact with minoxidil, call your vet or ASPCA Poison Control at 888-426-4435 right away6. Do not wait for symptoms. More in Minoxidil and cats: what to do at night.
Looking after the cap
Wash it at least once a week with your normal detergent and let it air dry. Wash it separately from pet bedding. If you have two, keep one on and one in the wash.