Compound

Topical Retinoid

Tretinoin or retinol nightly. Strongest topical for collagen and turnover.

Approved Verified 27 August 2026

What it does

The single best-studied topical for visible skin aging. Tretinoin (Rx) has the strongest evidence; retinol (OTC) is weaker but effective. Both increase collagen and cell turnover over months.

Retinoids bind nuclear retinoic-acid receptors, upregulating collagen-synthesis genes and accelerating keratinocyte turnover. Visible effects develop over 3 to 6 months of consistent use.

  • collagen synthesis
  • skin turnover
  • fine lines

What the evidence shows

Overall evidence strength: High certainty

Who it's for, who should skip

Visible skin aging. Start with a low concentration a few nights a week and build toward nightly. Pair with morning sunscreen — retinoids increase sun sensitivity and that pairing is non-negotiable.

Skip it if

  • pregnancy — Avoid retinoids during pregnancy. hard block

Running it

Form
topical
Dose
2–3x/week building to nightly · evening
Titration
start 0.025% tretinoin or equivalent retinol; build tolerance with lower concentrations

Safety

  • irritation, dryness, photosensitivity — build tolerance gradually common

Stacking & alternatives

Pair it with

  • daily morning sunscreen — Retinoids increase sun sensitivity; morning sunscreen is required, not optional. required · ongoing

Access & cost

Available over the counter. Look for: 0.025% tretinoin (Rx) or an OTC retinol; start low.

Last reviewed 27 August 2026. Regulatory status verified 27 August 2026.