Amy Glover / BuzzFeed / HuffPost My first experience with a hydrocolloid patch ― the generic name for the various pimple patches people apply to their faces ― actually had nothing to do with a spot. That’s because the same technology, and a lot of the same ingredients , are used on those blister patches you place on your ailing heel (fellow Docs lovers will know the pain). Advertisement But if I’m being totally honest, I had no idea why they shrunk my spots or healed my post-run bubble ― until I saw a TikTok from board-certified dermatologist Dr.

Witney Bowe . And yes, she did clarify what that white gunk is. How do they work? Speaking to the American Chemical Society (ACS) , Hadley King, M.

D., a board-certified dermatologist, said that the patches work by drawing moisture out of your skin. That way, they shrink the spot while covering it so it has room to heal.

The barrier means you can’t touch your spots, either. “As the hydrocolloid gel adheres to the skin, it absorbs excess oil and dirt away from pimples,” Dr. King told ACS .

Advertisement So it makes sense that, as Dr. Bowe explained in her Tiktok , the white spots you see after wearing patches overnight are not pus. “They’re actually the hydrocolloid material absorbing fluid, extra moisture, extra water, which thickens the hydrocolloid material and just makes it look a little bit whiter in those spots,” the doctor said .

Should I use pimple patches for serious acne? It’s not that you can’t use .