Why Peptides - Karen Lockyer Make Up Artist

Why Peptides?

So why are we hearing so much about Peptides in skincare?

Peptides has become a bit of a buzz word in skincare lately so I thought I would take a bit of a look. I do get baffled around a lot of scientific jargon, so I will keep it light.

Modern skincare uses synthetic or naturally derived peptides that are small enough to penetrate the outer skin layer (epidermis) and deliver targeted effects.

But What is a Peptide?

Peptides are short chains of amino acids — the same building blocks that make up proteins — but smaller in size. They are naturally present in our body and play a vital part in its function.

Functions in the body:
Peptides play many biological roles, such as:

Building blocks for many hormones
Without peptide-based hormones, your body couldn’t regulate critical processes like blood sugar, growth, reproduction, water balance and metabolism

Neurotransmitters: e.g., endorphines

Signaling molecules: regulate cell activity and communication

Antimicrobial peptides: help the immune system fight infection

How is this all relating to skincare, though?

Sometimes, peptides are manufactured outside the body for medical or cosmetic use.

Synthetic peptides are used because the body may not produce enough of a certain peptide naturally (e.g., growth hormone–releasing peptides).

Different Peptides have different functions for the skin and synthetic peptides are used to target specific functions (e.g., skin repair, muscle growth, or therapeutic drugs).

Type of Peptide	Function in Skin	Example Ingredients
Signal peptides	Stimulate collagen and elastin production	Palmitoyl pentapeptide-4 (Matrixyl)
Carrier peptides	Deliver trace minerals (like copper) to help healing and enzyme activity	Copper peptide (GHK-Cu)
Enzyme inhibitor peptides	Slow collagen breakdown by inhibiting enzymes like MMPs	Tripeptide-10 citrulline
Neurotransmitter-inhibiting peptides	Relax facial muscles (mild “Botox-like” effect)	Argireline (acetyl hexapeptide-8)
Antimicrobial peptides	Defend against bacteria and inflammation	Defensins, cathelicidins

Skincare is important, but always keep informed with what you are using. Sometimes less is best

The sell on using peptides in skincare is

Non-invasive anti-aging: Peptides can improve skin firmness and reduce wrinkles without injections.
Science-backed: Research shows some peptides really do increase collagen density or improve skin hydration.
Synergy with other actives: They work well with retinol, vitamin C, and niacinamide, enhancing repair without much irritation.
Biotech innovation: Advances in cosmetic chemistry allow for stable, skin-penetrating peptide formulations, which wasn’t possible a decade ago.

Collagen post menopause

Hold on a minute! In my many years as a beauty professional I have been led to believe that collagen molecules are too big to penetrate the skin, so not really possible to re introduce. In menopause our collagen supplies are very much depleted so I wanted to try and understand the claims in anti-ageing creams and if peptides make a difference to this. So I asked ChatGPT

Topical collagen (on the skin)

I was told I am 100% correct:
Collagen molecules are far too large to penetrate through the skin barrier (the stratum corneum).

Native collagen molecules are huge — often over 300,000 Daltons (Da) in molecular weight.
The skin’s upper layer only allows substances below ~500 Da to pass through.

So when you see “collagen cream”, it doesn’t mean collagen is literally entering your skin and rebuilding it. – I knew it!

Instead, topical collagen:

Acts as a moisturizing film on the surface, improving hydration and smoothness temporarily.
Can make the skin feel softer or plumper, but it does not replace lost collagen underneath.

That’s why peptides, retinoids, and vitamin C are favoured — they can stimulate your own fibroblasts to produce new collagen from within. Uh! Fibroblasts? So fibroblasts are the construction workers of your skin. They build, repair, and remodel the “scaffolding” that gives your skin strength and elasticity.

OK ,so now I want to know how can we stimulate collagen when our supplies are depleted after menopause. Im told:

Ah — now we’re getting into the core of aging and regenerative biology. Even if your body produces less collagen with age (or after menopause), it’s important to know that it doesn’t completely stop. You can still stimulate collagen synthesis — though the rate will naturally be lower than in youth.

So there is some hope!

My (POV ) Conclusion

I research and write this blog solely for my own enquiring mind to keep up with all things make up and beauty, I am no expert or scientist. I share incase anyone else might be curious too.

So from what I know and have recently read your natural Peptides should do the job, but new synthetic Peptides can help to hydrate and firm your skin. Collagen creams do not replace collagen, but acts as a moisturising film. We all have to make our own decisions on these things, but be warned things don’t always do what they say on the tin.