Anti-Aging Ingredients, Ranked by a Biologist

Here's the full breakdown:

1. Growth factors

   S

   What it is: cellular messengers that signal your skin to make collagen, renew, and repair — a similar principle to PRP. Evidence: systematic reviews of topical growth-factor serums show real dermal and epidermal restructuring for photoaging. [1]

   Recommended Products

   Longevity Protocol · TNS Skinmedica · (plated)

2. Niacinamide

   S

   What it does: fades and prevents dark spots, supports the skin barrier, and helps defend against UV / photo-damage. [2] Why it's S: strong, repeated clinical support across those uses. Caveat: don't overdo it (beyond 5%) — very high percentages can irritate. No need for an extra niacinamide serum, just get a moisturizer that contains it.

   Recommended Products

   EltaMD AM Restore Moisturizer · Darkfin Labs Serum + Moisturizer

3. GHK-Cu (copper peptide)

   A

   What it is: a copper peptide with real collagen-signaling data behind it. [3] Caveat: can irritate sensitive skin and cause breakouts — patch-test and go slow.

   Recommended Products

   Allies of Skin · The Ordinary

4. Tretinoin

   A

   What it does: fantastic for cell turnover, dark spots, and overall anti-aging — the most studied molecule in modern skincare. [4] Caveat: can severely irritate; needs easing-in (and a prescription). Use the sandwich method at first (moisturizer, pea-size tret, then moisturizer) and start 2-3x a week only.

   Recommended Products: N/A

   See your doctor or dermatologist; start at the lowest dose

5. Squalane

   A

   What it is: mimics the oil your skin already makes (sebum), so it repairs the barrier without clogging or breaking you out. Why it's A: low-drama, high-tolerability workhorse. (Widely accepted — see note under Receipts.)

   Recommended Products

   100% Plant-Derived Squalane (Sephora) · Darkfin Labs Longevity Protocol

6. Retinol

   B+

   What it does: it works — but your skin has to convert it through several steps into retinoic acid before it can use it, which makes it meaningfully weaker than tretinoin (already retinoic acid). [4] Why B+: a solid, more tolerable entry point to retinoids.

7. Volufiline

   B

   Claim: marketed for a "plumping" effect. Evidence: not much independent data — mostly manufacturer-level. Anecdotally, used under the eyes with a little improvement.

8. NAD+

   B

   What it is: not very bioavailable to skin on its own — the molecule struggles to get where it needs to go. Better option: precursors, or ingredients that stimulate the pathway's enzymes, tend to work better topically.

9. Hyaluronic acid

   C

   Watch-out: in a dry climate it can pull water from deeper in your skin and let it evaporate off the surface — making dry skin worse. [5] Nuance: it can hydrate when you seal it with a moisturizer on top, so it's not useless — just widely misused.

10. Collagen (topical)

    C

    Why C: your skin can't absorb it — the molecules are too large to get past the barrier. [6] What it actually does: sits on the surface and hydrates as a film; it isn't rebuilding collagen from a cream.

11. PDRN (salmon DNA)

    C

    Where it works: real rejuvenation results come from in-clinic injections or microneedling. [7] Topically: absorption is inconsistent, so a serum won't match the clinic.

12. Peptides

    Depends

    Reality: "peptide" just means a chain of amino acids — there are many, and they're not one thing. Best for topical anti-aging: GHK-Cu, growth-factor peptides, and Matrixyl. Judge the specific peptide, not the word on the label.