The Peptide Periodic Table

Clinical Benchmark

2009 double-blind RCT (n=93, Sederma) — 10% Matrixyl reduced wrinkle depth by 45% over 2 months. 5% shows significant collagen increase at 8 weeks (2024 independent study).

Concentration Threshold

5–10% is clinically validated. Dose-response plateaus above 10%. Most prestige brands use 0.5–1% (sub-clinical).

Field Test — INCI Position Test

Find 'Palmitoyl Tetrapeptide-7' in the ingredient list. Position 1–5 = 5%+. Position 6–10 = 1–5%. Position 15+ = likely sub-clinical (<0.5%).

Clinical Benchmark

2001 study (Pickart, Margolina) — 0.1% GHK-Cu significantly improved wound healing. 2012 trial — 1% GHK-Cu improved skin density and reduced laxity at 12 weeks. Hair growth studies: 1% extends the anagen phase in miniaturised follicles.

Concentration Threshold

1% is the anti-aging clinical benchmark. Most retail products don't disclose concentration. True 1% GHK-Cu has a faint blue tint.

Field Test — The Blue Tint Test

A genuine 1%+ GHK-Cu serum has a faint blue or greenish tint (copper ions absorb red/orange wavelengths). A completely clear 'copper peptide serum' either has sub-clinical copper, pre-chelated copper, or oxidised copper.

Clinical Benchmark

2002 study (Lipotec) — 10% Argireline reduced wrinkle depth around eyes by 30% at 30 days. 2023 independent RCT — 10% reduced crow's feet severity by 17% at 8 weeks. Effect is additive with retinoids.

Concentration Threshold

10% is the threshold for measurable effect. Below 5%, SNAP-25 competition is insufficient. Most products contain 3–5% (subjective improvement but marginal quantifiable effect).

Field Test — The 30-Day Split Test

Apply 10% Argireline to one side of the face only (crow's feet), evenings, for 30 days. Compare both sides in neutral light. Works only on dynamic wrinkles (expression lines) — not static lines, not volume loss.