Dr. Dustin Portela.

"First up is Nizoral shampoo, which contains ketoconazole, a common antifungal agent. This is my go-to recommendation over-the-counter. It's a true antifungal and directly targets the malassezia. You can get the one percent version over the counter at pretty much any pharmacy or off Amazon, and if your case is more stubborn there's a two percent ketoconazole version available by prescription."

"Selsun Blue is the classic selenium sulfide shampoo you can get over the counter. Selenium sulfide has antifungal properties and works well for seborrheic dermatitis. You wash it in, leave it for five minutes, then rinse it out. Some people can find this one a little bit more drying, so if you have naturally dry skin underneath, just keep that in mind. It doesn't irritate everybody."

"If you're going to add one proven active on top of your basics, I'd recommend a retinoid, and your late twenties or early thirties is a great time to start thinking about it. AlphaRet from SkinBetter Science gives you prescription retinoid level results in my opinion, with a gentler experience, and that's where I'd put my money. I'd be using something like that before I'd put anything on my skin with longevity on the label."