Peptides

Peptide1–5%

Short chains of amino acids that act as messengers, helping skin look firmer and smoother over time.

What it is

Peptides are short chains of amino acids, the building blocks of proteins. Different peptides are designed to help the appearance of fine lines, firmness or tired-looking skin. They are gentle and fit most routines, but results depend heavily on which peptide is used and at what dose.

Good for

Fine linesFirmnessMature skinSensitive skin

How it works

Signal peptides such as palmitoyl tripeptide-1 mimic fragments of collagen and are thought to encourage skin to make more of its supporting proteins. Carrier peptides like copper tripeptide-1 deliver copper used in skin renewal. Neurotransmitter-type peptides such as acetyl hexapeptide-8 are designed to soften the look of expression lines.

Ratings

Evidence

3/5

Some peptides have controlled trials, but many studies are small.

Gentleness

5/5

Very low irritation, suiting sensitive skin and eye products.

Formulation difficulty

3/5

Sensitive to heat and pH, and copper peptides clash with acids.

Cost

4/5

Branded blends are costly per kilo and need the recommended dose.

Popularity

5/5

Searches grew through 2024–25 and peptides lead many new launches.

Pairs and cautions

Pairs well with

In a routine. Pairing in one formula depends on matching pH windows.

Take care with

Vitamin C with copper peptidesCopper speeds oxidation
Strong acids or oxidisersPeptides are pH-sensitive

Formulations it suits

Serum Cream Eye cream Sheet mask

Packaging

Regional considerations

Australia	AIIC listings limit palmitoyl tripeptide-1 to 0.002% and palmitoyl pentapeptide-4 to 0.0005% in skin cosmetics, not for use in the eye; other peptides need AICIS categorisation.
United States	FDA treats claims that a product removes wrinkles or increases collagen production as drug claims, so peptide marketing must stay with 'helps the appearance of' wording.

In the lab

Specifications

Typical use level

1–5%0525%

pH window

pH 5–72 acid7 neutral10 alkaline

Solubility

Water-solubleOil-dispersible

Sensitive to

HeatLow pH

Supplier blends at 1–5%, such as Matrixyl 3000 at 3%, leave the peptide itself at parts per million; copper tripeptide-1 is used at 0.05–1%.

INCI	Palmitoyl Tripeptide-1; Palmitoyl Tetrapeptide-7; Palmitoyl Pentapeptide-4; Copper Tripeptide-1; Acetyl Hexapeptide-8
Also known as	Matrixyl, Copper peptides (GHK-Cu), Argireline, Signal peptides
Origin	synthetic

Lab notes

Solubility and phase

Water phase for most supplier solutions, which are water- or glycol-based. Palmitoylated peptides may need glycols or oil-compatible carriers.

Stability

Add below 40 °C in cool-down. With copper peptides, leave out chelators such as EDTA and reducing agents, and allow for a blue tint.

Regulatory, Australia

Palmitoyl tripeptide-1 and palmitoyl pentapeptide-4 are on the AIIC, but copper tripeptide-1, acetyl hexapeptide-8 and palmitoyl tetrapeptide-7 were not on the public June 2026 download, so confirm AICIS categorisation. Copper compounds are scheduled only above 5%, and there is no EU restriction.

Claims to take care with

Supplier lab data cannot be presented as finished-product results. Avoid 'Botox-like', 'rebuilds collagen' and 'heals' wording.