Is 'Peptide 21' really 21 peptides?

Yes, in the sense that 21 distinct peptide/neuropeptide molecules appear on the INCI list. But concentrations for most of them are low — peptides 5-21 are each present at trace amounts. The main drivers are Argireline, Matrixyl, and copper tripeptide, consistent with most multi-peptide serums.

Why is this $95 when The Ordinary's Buffet is $28?

Brand positioning, texture engineering, and retail markup — not substantially different peptide exposure. If you love the texture and brand experience, fine. If you care about peptide dose per dollar, the lower-priced alternatives are mathematically better.

serum30ml

Peptide 21 Wrinkle Resist Serum

Name: Peptide 21 Wrinkle Resist Serum
Brand: Peter Thomas Roth
Availability: InStock

Peter Thomas Roth

Peter Thomas Roth's Peptide 21 range is built around the marketing claim of '21 peptides and neuropeptides' — in practice a stack of well-known cosmetic peptides (including Argireline, Matrixyl-family palmitoyl peptides, and copper tripeptide) plus proprietary neuropeptide complexes whose individual evidence is weaker but mechanism story is compelling. The serum form is lighter than the PTR Peptide 21 cream and moisturizer, making it easier to layer. The $95 price point reflects premium positioning rather than unique ingredient access — the same peptide molecules appear at $15-30 in The Ordinary, Paula's Choice, or INKEY List formats.

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Peptides in this product

Argireline (Acetyl Hexapeptide-8)

Expression-line softening

Matrixyl 3000 (Palmitoyl Tripeptide-1 + Palmitoyl Tetrapeptide-7)

Collagen signaling

GHK-Cu (Copper Tripeptide-1)

Collagen + antioxidant activity

Targets

Peptides for Anti-Aging Peptides for Skin & Glow

Key ingredients

Acetyl Hexapeptide-8Palmitoyl Pentapeptide-4Copper Tripeptide-1SqualaneHyaluronic Acid

How to use

Apply 3-4 drops AM and PM to clean skin before heavier creams. Can be layered with retinoids (PM) and vitamin C (AM — but not in the same routine as the product, since it contains copper tripeptide).