Peptides vs retinol: which one should you use?

Peptides now get more searches than retinol in the US, and many people are choosing them because retinol stings. That's a fair reason, as long as you know what you're trading.

• Retinoids: decades of controlled trials. Prescription tretinoin improves fine lines and sun damage; over-the-counter retinol improved fine wrinkles in a 24-week controlled study.
• Peptides: a handful of small, mostly manufacturer-run trials showing modest improvements in fine lines over 4 to 12 weeks.
• Tolerance: peptides almost never irritate. Retinoids often cause dryness and peeling at first.

In an 8-week randomized study of 196 women, a regimen of niacinamide, peptide and retinyl propionate products improved wrinkle appearance about as much as prescription 0.02% tretinoin, and it was better tolerated. The study was run by the product maker, and the cosmetic regimen contained several actives, so it doesn't show what peptides do alone.

• Want the most evidence and can tolerate some adjustment: start a retinoid slowly.
• Very sensitive skin, rosacea-prone or eczema-prone skin: peptides are an easier start.
• Pregnant or trying: retinoids are usually avoided; check with your doctor. Peptides are a common alternative.
• Want both: retinoid at night, peptide serum in the morning or on off nights.

Retinoids act on nuclear receptors that switch on collagen-related genes and speed skin turnover. Peptides are designed to send narrower signals. That broader action is a large part of why retinoids show bigger effects, and more irritation.

• Retinoids for fine lines and sun damage.well-supported
• Peptides for fine lines.limited evidence
• A peptide plus niacinamide plus retinyl propionate regimen as a tolerable alternative to tretinoin.limited evidence

• Peptides matching retinoids on their own.