This Is What Happens To Your Skin If You Leave A Hydrocolloid Patch On Too Long

The "magic" of a hydrocolloid patch is really in the science. As explained to Well+Good by board-certified dermatologist Hadley King, "The hydrocolloid sheet works by absorbing excess fluid, and this pulls oil and dirt away from the pimple." So in other words, it whisks away all the icky stuff inside of the zit. That sounds great, and it means we should put one on every spot we see, right? Not so fast. As it turns out, not all pimples respond equally to these patches. 

According to Dr. Morgan Rabach, a dermatologist from LM Medical, these patches are ideal for whiteheads, but not cystic acne that sits below the surface of the skin. "There has to be some connection to the fluid in the patch otherwise there is no way for the patch to access what's inside," the expert told Men's Health.

Timing also matters. "If you put one on before the pimple has popped and gotten infected by more bacteria, it will make the skin heal faster," Rabach confirmed. The best times to apply these patches is when a pimple is almost to the surface or has just popped. This way it can maximize its ability to absorb the fluids inside and subsequently prevent scarring.