Peptide serums are everywhere, but the names on the label — Argireline, Matrixyl, SNAP-8, GHK-Cu — rarely explain what each one is for. This guide compares the four most popular cosmetic peptides for the look of fine lines, so you can pick the right one, or the right combination.
Two types of lines, two types of peptide
It helps to think about fine lines in two groups:
- Expression lines — crow's feet, forehead lines and frown lines that show most when you smile, squint or raise your brows.
- Texture and firmness — lines and crepiness that come with skin looking less plump and bouncy over time, along with sun exposure.
Cosmetic peptides are generally chosen with one of these in mind.
Argireline (acetyl hexapeptide-8)
Argireline is the best-known "expression line" peptide. It's used in serums around the eyes and forehead for a smoother, more relaxed-looking appearance. It's water-soluble, gentle and easy to formulate. Typical use is around 5–10% of a ready-made Argireline solution, or the equivalent amount of powder. Read the full Argireline guide.
Good for: crow's feet and forehead areas; people who want a gentle, non-irritating option.
SNAP-8 (acetyl octapeptide-3)
SNAP-8 is a longer cousin of Argireline and is used for the same purpose: the look of expression lines. Some formulators prefer it or use the two together. Like Argireline, it's gentle and suits eye-area serums and roll-ons. See the SNAP-8 guide.
Good for: people who already like Argireline and want to try a step up, or combine both.
Matrixyl (palmitoyl pentapeptide-4)
Matrixyl is a "signal" peptide used for skin that looks firmer, plumper and smoother over time. It's less about expression and more about overall texture. It's a long-standing staple in anti-ageing cosmetic creams and serums. See the Matrixyl guide.
Good for: general texture and firmness on the face and neck; daytime use under sunscreen.
GHK-Cu (copper tripeptide-1)
GHK-Cu is the blue copper peptide, used for skin that looks firmer, smoother and more radiant. It's typically a night serum and is popular as a gentler alternative to retinol. It's the most "personality-driven" of the four: it needs a skin-friendly pH and shouldn't be mixed with vitamin C or acids. See the GHK-Cu guide.
Good for: overall radiance, firmness and texture; people who find retinol too much.
Comparison table
| Peptide | Main focus | Best time | Gentleness | Plays well with |
|---|---|---|---|---|
| Argireline | Look of expression lines | AM or PM | Very gentle | Almost everything |
| SNAP-8 | Look of expression lines | AM or PM | Very gentle | Almost everything |
| Matrixyl | Firmer, smoother-looking skin | AM or PM | Very gentle | Most actives |
| GHK-Cu | Radiance, firmness, texture | PM | Gentle | Hyaluronic acid, niacinamide, other peptides |
So which is "best"?
There's no single winner. It depends on what you're looking at in the mirror:
- Lines that show when you move your face: start with Argireline or SNAP-8.
- Skin that looks less firm or crepey: start with Matrixyl or GHK-Cu.
- A bit of both: combine an expression-line peptide in the morning with GHK-Cu at night.
Be realistic: cosmetic peptides are subtle. Published studies are generally small, often funded by ingredient makers, and results depend heavily on the formula. Daily sunscreen does more for the long-term look of your skin than any serum.
A simple peptide routine
- Morning: cleanse → Argireline/SNAP-8 or Matrixyl serum → moisturiser → SPF 50+.
- Night: cleanse → GHK-Cu serum → moisturiser.
- If you use retinol, put it on alternate nights to GHK-Cu (see GHK-Cu vs retinol).
Introduce one new serum at a time, two to three weeks apart, so you know how your skin responds. Always patch test — see our patch testing guide.
Can you mix peptides in one bottle?
Yes, many DIY formulators combine Argireline and Matrixyl, or Argireline and SNAP-8, in one water-based serum. GHK-Cu can also be combined with other peptides at a pH of around 5.5–6.5, though we'd suggest getting comfortable with each one on its own first.
Shop peptide skincare
Our GHK-Cu range includes DIY serum kits, ready-made serum Shop now and cream Shop now. Argireline, Matrixyl and SNAP-8 options are also available — check the skincare catalogue for what's currently available.
How to judge whether a peptide is working for you
Peptide results are gradual, which makes them easy to under- or over-estimate. A simple method helps:
- Take a photo in natural daylight, same spot, same time of day, no make-up, before you start.
- Use one new peptide product consistently for 8–12 weeks without changing the rest of your routine.
- Take matching photos every four weeks and compare them side by side.
Look for how smooth, even and hydrated your skin looks, not just individual lines. If you can't see a difference after three months, try a different peptide rather than simply using more.
FAQ
Is Argireline "Botox in a bottle"?
No. That's a marketing phrase. Argireline is a cosmetic ingredient for the appearance of expression lines, and topical serums don't work like injectable medicines.
Can I use Argireline and GHK-Cu together?
Yes. A common routine is Argireline in the morning and GHK-Cu at night.
How long until I see a difference?
Give any peptide at least 8–12 weeks of consistent use before judging it.
Are peptides safe for sensitive skin?
They're generally among the gentlest actives, but anyone can react to any ingredient. Patch test first.
Which peptide is best for under the eyes?
Argireline and SNAP-8 are the most popular in eye-area products. Keep products away from the eye itself.
Every peptide we use is independently lab-tested for identity and purity before it goes into our creams and serums. For laboratory research materials, see Ultimate Peps; lab testing is available from QLD Analytical (Queensland, Australia).
For topical cosmetic use only. Not intended to diagnose, treat, cure or prevent any disease. Individual results vary. — The Ultimate Performance Team