Yes, sleeping in a hydrocolloid patch is one of the ideal times to wear one, because your skin gets uninterrupted hours to rest while the patch absorbs fluid and keeps your fingers off the spot. Our Overnight Spot Cover is made for exactly this, with multi-size medical-grade hydrocolloid (8mm, 10mm, and 12mm) and extra hold so it stays put through pillow friction and tossing. Cleanse, pat fully dry, press the patch on, and head to bed. In the morning, peel it off gently and you'll usually see the patch has turned cloudy white where it's been working. If you're a side sleeper, the strong adhesive really helps it stay through the night.