When it comes to building an effective skincare routine, more isn’t always better. In fact, using the wrong ingredients together can actually make your products less effective—or even completely useless. According to board-certified dermatologist Dr. Mamina Turegano (aka Dr. Momina on TikTok), there’s one specific duo that you definitely shouldn’t be layering in the same routine: benzoyl peroxide and tretinoin.
@dr.mamina Were you aware of this before seeing this video?! #benzoylperoxide #tretinoin #acne #skincaretips #dermatologist #skincare original sound – Dr. Mamina Turegano, MD
Why You Should Not Mix Benzoyl Peroxide And Tretinoin
“Benzoyl peroxide can help with acne—so can tretinoin—and oftentimes, people will be using both in the same routine,” she explains in her video. While each ingredient is powerful on its own, pairing them the wrong way can backfire. “If you use a leave-on benzoyl peroxide, it can actually inactivate tretinoin,” she warns.
So what should you do instead? Dr. Mamina says the key is timing and formulation. “You either want to use them separately—like benzoyl peroxide in the morning and tretinoin at night—or use a benzoyl peroxide wash, where it’s rinsed off, followed by tretinoin.”
The bottom line
There are exceptions, she adds, such as specially formulated products that combine both ingredients using microencapsulation technology—but unless you’re using one of those, it’s best to play it safe. “I would not use two separate benzoyl peroxide and tretinoin products in the same routine,” she says.
The takeaway? These are two powerhouse acne-fighting ingredients—but only when used correctly. Mixing them the wrong way could mean you’re not getting the full benefits of either.
