THE EVIDENCE MAP
What matters more than what
14 skincare ingredients ranked by how much they outperform the alternative — based on head-to-head clinical trials with PubMed-cited sources. Not opinions. Not ingredient hype. Comparative effect sizes.
Version 1 — March 2026 · Updated when new evidence changes the rankings
This map changes when the evidence does
I update these rankings every time a new head-to-head trial shifts the data. Subscribe to get notified when something moves — and get the weekly evidence breakdown that feeds this map.
One comparison per week. Unsubscribe anytime.
The rankings
Effect size = how much better than the comparison. A 2x ratio means the ingredient produced twice the improvement. Higher is more impactful.
Outperforms placebo for redness reduction
FDA-approved for rosacea (Rhofade). The active ingredient in Afrin nasal spray.
Outperforms placebo for pigmentation reduction
Strongest effect size in the dataset — but growth factors degrade in standard packaging.
Outperforms placebo for pigmentation reduction
At 2–5%. The 10% serums have limited evidence supporting their superiority.
Outperforms placebo for pigmentation reduction
A derivative of salicylic acid with gentler exfoliation.
Outperforms placebo for surface smoothness
Fourth-generation retinoid. Targets RAR-gamma selectively — less irritation than tretinoin.
Outperforms placebo for pore refinement
A vitamin D analogue, typically prescription. Used off-label for skin texture.
Outperforms placebo for pigmentation reduction
Derived from milk thistle. Performed meaningfully in a head-to-head trial against hydroquinone.
Outperforms silymarin for pigmentation reduction
The traditional gold standard for dark spots. Four alternatives now match it in trials.
Outperforms placebo for wrinkle reduction
Strongest evidence is for oral supplements, not topical serums.
Outperforms placebo for pigmentation reduction
Matched hydroquinone with a better safety profile — no irritation, no rebound.
Outperforms placebo for redness reduction
Originally a surgical anti-bleeding drug. Also reduces pigmentation (its primary use in skincare).
Outperforms tretinoin for surface smoothness
Within 9% of prescription tretinoin at 12 weeks — with half the side effects.
Comparable to placebo for oil balance
Effective for oil at clinical concentrations (20–70%), not the 5–10% in OTC toners.
Comparable to tranexamic acid for pigmentation reduction
Comparable to tranexamic acid — but unstable. Oxidized vitamin C may generate free radicals.
How to read this map
Each bar shows an ingredient's best effect size from a direct (non-transitive) clinical trial. A 6x ratio means the ingredient produced 6 times the improvement of the comparison group.
Gold Standard means the trial was randomized, double-blind, and used a controlled design (the highest evidence tier). Strong means two of those three criteria were met.
This map shows the single best effect size per ingredient — not the average. Some ingredients (like EGF) have dramatic results in one specific context but limited evidence in others. The notes below each bar explain the caveats.
The comparison column matters. An ingredient that outperforms placebo by 2x is different from one that matches hydroquinone at 1x. Context is everything — which is why the notes exist.
The evidence behind each ranking
Every ranking on this map links back to a clinical trial. I break down one comparison per week — the study design, the numbers, and what it means for your routine.
One comparison per week. Unsubscribe anytime.