Anyone who tries to google skincare products hits a brick wall of fake reviews, SEO spam and hysterical pseudoscientific terror. Vogue's Christina Mueller writes that the blind-studied, peer-reviewed answer to your question is probably "Retinol":
Imagine for a moment that a revolutionary skin-care ingredient was discovered. It visibly smoothed out wrinkles and obliterated breakouts; it improved skin texture and tightened pores into tiny little nothings. ... Such an ingredient does exist, and chances are some form of it is currently languishing in a corner of your medicine cabinet. It’s retinol. It isn’t sexy. It definitely isn’t new. In fact, it was discovered 81 years ago, making it a veritable dowager compared with all the fresh new super-ingredients that have since come onto the anti-aging scene. For the past few decades, it has been hiding in plain sight—but with a few new developments, it is stepping back into the limelight.
Yes, my fellow gentlemen with bad skin, listen to what Vogue is telling you! What finally worked for my complexion was giving up on horrible acne treatments like benzoyl peroxide and antibacterial cleanser. Reading the relevant scientific studies—many of which are decades-old—revealed counterintuitive suggestions.
First, what I thought was acne turned out to be mild rosacea. Innocuous stuff like sugar and caffeine, reflectively ruled out when acne is assumed, are common triggers for superficially similar conditions. Letting my skin be naturally oily when it "wanted" to be (and even made moreso, with Jojoba oil) makes it look less so--and healthier--in the long run. And, finally, unsexy vitamin A derivatives are among very few chemicals shown by research to improve skin condition. Don't go crazy with prescription-strength Retin-A, as you'll just peel and freak out. Just start with some retinol night cream from Rite Aid or Target and give it a try.