The Beginner's Guide to Peptides in Skincare — and Why Every Serious Formulator Should Know Them
By The Sourcery | Cosmetic Actives
If you've spent any time in the skincare world recently, you've probably noticed peptides everywhere — in serums, eye creams, anti-ageing boosters, and increasingly on the ingredient lists of cult-favourite products. But what actually are they, and how do you use them in your own formulations?
This guide covers the basics — from what peptides are to practical formulation tips for the ones we stock at The Sourcery.
What is a peptide?
A peptide is a short chain of amino acids — the same building blocks that make up proteins like collagen, elastin, and keratin. The difference between a peptide and a full protein is simply length: peptides are typically 2 to 50 amino acids long, while proteins are much larger.
In skincare, peptides are popular cosmetic actives because they are often described as "messenger" ingredients, each chosen to target a particular aspect of skin appearance — such as the look of fine lines, firmness, smoothness or radiance.
This is what makes peptides so interesting to formulators and so different from, say, a simple moisturising ingredient or an exfoliant.
The main types of cosmetic peptides
Peptides are usually grouped into a few families, depending on how their suppliers describe them:
Signal peptides are used in formulations designed to support the look of firm, smooth, plumper-looking skin.
Neurotransmitter-affecting peptides (sometimes called neuropeptides) are used in products aimed at softening the appearance of expression lines — crow's feet, forehead lines and frown lines.
Carrier peptides deliver trace minerals — most notably copper — and are used in conditioning and anti-ageing-style formulations.
Enzyme-inhibiting peptides are used in formulations designed to help maintain the look of firm, supple skin.
The real appeal of peptides in formulation is that you can combine different types in one product — a multi-peptide approach that goes well beyond basic moisturising.
The peptides we stock at The Sourcery
Here's a breakdown of each peptide in our range, what it's used for, and how to formulate with it.
SNAP-8 — Acetyl Octapeptide-3
Snap-8 is an 8-amino-acid synthetic peptide modelled on part of the SNAP-25 protein. It is widely used in serums and eye products designed to visibly soften the appearance of expression lines.
Best for: Products targeting the look of crow's feet, forehead lines and frown lines; eye contour products. Use level: 3–10% in leave-on formulations. Formulation notes: Water soluble — add to the water phase. Stable at typical cosmetic pH. Often combined with Argireline, and with Matrixyl for a multi-peptide formula.
ARGIRELINE — Acetyl Hexapeptide-8
Argireline is the shorter predecessor to Snap-8 — a 6-amino-acid peptide from the same family. It was one of the first widely commercialised expression-line peptides and remains a staple in anti-ageing formulation.
Best for: Forehead and eye area serums, and any anti-ageing product targeting the appearance of expression lines. Use level: 5–10% in leave-on formulations. Formulation notes: Water soluble, easy to incorporate. Can be combined with Snap-8.
GHK-CU — Copper Tripeptide-1 (1000ppm solution)
GHK-Cu is one of the best-known and most versatile peptides in cosmetic science. It's a tripeptide (glycyl-histidyl-lysine) bound to a copper ion, and is used in serums and creams to help skin look smoother, firmer and more even. It is effective at low use levels.
Best for: Anti-ageing serums, eye creams and skin conditioning products. Use level: 1–10% of the 1000ppm ready-to-use solution in finished formulations. Formulation notes: The blue-green colour is natural and expected. Avoid high-dose Vitamin C (ascorbic acid) in the same formula as it can complex with copper ions. Compatible with most other actives including hyaluronic acid, niacinamide, and other peptides.
MATRIXYL 3000 — Palmitoyl Tripeptide-1 & Palmitoyl Tetrapeptide-7
Matrixyl 3000 is a blend of two palmitoyl peptides that are used together in formulations designed to visibly reduce the look of wrinkles and help skin look firmer over time.
Best for: Anti-ageing serums, moisturisers, neck creams, eye creams, and any formulation targeting the look of fine lines and firmness. Use level: 3–8% in leave-on formulations. Formulation notes: The palmitoyl chain gives good affinity with the skin's lipid barrier. Works beautifully alongside GHK-Cu and Snap-8 in a multi-peptide serum.
PALMITOYL TRIPEPTIDE-5 — Syncol
Palmitoyl Tripeptide-5 is a popular peptide for anti-wrinkle formulations, used to help improve the look of wrinkles and skin texture.
Best for: Anti-wrinkle serums, moisturisers and firming creams. Use level: 3–5% in leave-on formulations. Formulation notes: Water dispersible. Combines well with other signal peptides and with hyaluronic acid for a hydrating, smoothing formula.
How to combine peptides effectively
One of the great advantages of peptides is that they can be stacked in one formula. A well-designed multi-peptide serum might combine:
- An expression-line peptide (Snap-8 + Argireline) to soften the look of expression lines
- A firming peptide (Matrixyl 3000 or Palmitoyl Tripeptide-5) for the look of smoother, firmer skin
- A copper peptide (GHK-Cu) for skin conditioning
This multi-peptide approach is how professional-grade formulations differentiate themselves from basic anti-ageing moisturisers.
General formulation tips
- Add peptides to the water phase at or below 40°C — heat can degrade them
- Keep pH between 4.5 and 7 for most peptides — check individual specifications
- Avoid high-concentration ascorbic acid in the same formula as copper peptides
- Use at the lower end of the range first and build up — more is not always better with actives
- Fragrance-free formulations are best practice with peptide serums, especially for sensitive-feeling skin
- Preserve properly — peptide serums are typically water-based and need a robust broad-spectrum preservative
Where to start
If you're new to formulating with peptides, a simple starting point is a water-based serum with:
- Hyaluronic acid (1–2%) as a hydrating base
- Matrixyl 3000 (5%) for the look of firmer skin
- Snap-8 or Argireline (5–8%) for the look of expression lines
- A light thickener like xanthan gum (0.3–0.5%)
- Preservative to specification
- pH adjusted to 5.5–6.5
It's a straightforward formula with a strong active story — a great first peptide serum.
At The Sourcery, we don't just sell ingredients — we help you understand how to use them. If you have questions about which peptides suit your formulation goals, what use levels to start with, or how to combine them effectively, get in touch at info@thesourcery.co.nz — we're here to help, for batches big and small.