17 September 2021
Are peptides the next holy grail in skincare? Peptides are on the trending buzzwords in skincare; with their presence ubiquitous in many anti-ageing skincare products. Peptides or polypeptides are thought to boost the skin’s collagen reserves and soften wrinkles. Hence, many peptide infused products are often touted as botox in a jar or topical alternative to collagen boosting skin treatments. Not surprisingly, peptide skincare products also come at a cost to consumers. Today’s blogpost is a guide to peptides skincare and all the science and data on this fancy ingredient.
Peptides are short chains of amino acids, which form the building block for proteins. When many peptides are joint together, they form proteins like collagen in the skin. There are 20 different types of amino acids in the human body. Different combinations and permutations of amino acids create different types of peptides with different biological functions.
With the numerous peptides available, it is more helpful to recognise the 5 main types of peptides for an overview.
1. Signal peptides
The most commonly used of all peptides in skincare, signal peptides increase collagen levels in the skin. They do this by signalling to the collagen producing cells called fibroblasts to enhance collagen synthesis through different biochemical pathways. Some signal peptides also increase elastin levels and reduce pigmentation formation in the skin.
Some of the presumed benefits of signal peptides are thicker, firmer and more youthful looking skin. Signal peptides are often found in anti-ageing beauty products for fine wrinkles, laxity and hyperpigmentation.
Carrier peptides are the second most commonly used of peptides in cosmetics. One of the most well known carrier peptides is copper peptides. These peptides improve skin firmness and texture and diminish fine wrinkles. Carrier peptides stabilise and deliver copper ions to enzymes in the skin for wound healing and collagen synthesis.
Neurotransmitter inhibiting peptides
Neurotransmitter inhibiting peptides are the newest peptides in cosmeceuticals. These peptides were developed to mimic the action of Botulinum toxin. Neurotransmitter inhibiting peptides block the release of a chemical called acetylcholine at the neuromuscular junction to inhibit muscle contraction and relaxation.
For neurotransmitter inhibiting peptides in skincare to simulate Botox’s wrinkles removing effects, it is necessary for these peptides to penetrate the skin and deeper tissues to reach the facial muscles of interest. This presents a major limitation in the efficacy of neurotransmitter inhibiting peptides in skincare.
Examples of neurotransmitter inhibiting peptides used in skincare are Argireline (Acetyl-glutamyl-glutamyl-methoxil-glutaminyl-arginyl-arginylamide), Vialox (Pentapeptide-3) and Leuphasyl (amino acid sequence not publicly disclosed).
Enzyme inhibitor peptides
As the name suggests, enzyme inhibitor peptides block the activity of enzymes that disintegrate protein structures in the skin like collagen. In doing so, enzyme inhibitor proteins delay collagen loss in the skin to stave off signs of ageing. Soy extract, rice peptides and silk peptides are some examples of enzyme inhibitor peptides.
Structural peptides are fragments of structural proteins such as keratin. An example would be keratin peptides.These peptides supposedly reduce hair and nail brittleness and improve skin barrier function
Based on this understanding of the functions of various peptides, these are the theoretical benefits of peptide skincare:
• Reduced wrinkles
• Firmer, smoother skin
• Stronger skin barrier
• Improved skin hydration
• Lightened hyperpigmentation
Normal and older skin
There are some studies and data to support these claims regarding peptides in skincare products. However, these studies have been limited tomostly in-vitro studies using silicone replicas on the skin. The findings from these studies may not be replicated in humans in real life settings due to intrinsic differences between the silicone replicas and human skin.
Clinical trials on peptide skincare have been performed- but those have also been limited to small, open label studies mostly sponsored by cosmeceutical companies. Large, double blinded, randomised controlled trials would be more convincing.
One of the biggest weaknesses with peptide skincare lies in the poor absorption of peptides across the skin. For an active ingredient to work, it needs to penetrate the skin to reach target cells, like fibroblasts in the dermis to boost collagen synthesis.
Transdermal delivery and efficacy of peptides are a challenge because of the inherent biochemical structure of peptides. Peptides tend to have large molecular weight and low lipophilicity; which makes it difficult for peptide molecules to diffuse across the stratum corneum of the skin. I have not come across any examples of peptide products that can remove wrinkles the way Botox can. I’m certain many doctors feel the same way too. Similarly, collagen building treatments such as Profhilo and Fractional CO2 laser offer more convincing results than peptide skincare.
To overcome this major obstacle preventing peptide absorption, several new drug delivery systems have been used. Examples of these novel delivery systems include encapsulation of peptides (e.g. liposomes), penetration enhancers, co-administration of peptide sequences, and modified peptides. Treatments like iontophoresis and microneedling *may* also improve the skin’s permeability towards peptides.
So far, peptides skincare products seem to be very safe. As a relatively new active ingredient with relatively little studies behind them, not much is known about the side effects of peptide skincare.
Peptide products can be found in serums and moisturisers, over the counter. You can use it in the day and/or night if you would like. The optimum concentration and pH of peptide products remains unclear- so the jury’s still out there on that. As peptides are unable to diffuse across the skin on their own, my recommendation is to look for peptides products that are enhanced with delivery systems that improve uptake (e.g. encapsulation).
Another tip with using peptides: be gentle. These fragile molecules can suffer a change in their molecular structure with change in pH and temperature. Hence, avoid using acids like AHA and BHAs and beauty tech devices that emit heat when using peptide skincare products.
The Ordinary’s Buffet is really what its name suggests- a buffet of peptides for a supposed array of benefits to the skin. Decoding the ingredients in The Ordinary’s “Buffet” The main peptides in The Ordinary’s “Buffet” are:
• Matrixyl 3000 peptide complex: a common ingredient in anti-aging and anti-wrinkle skincare Increases collagen formation in the skin
• Matrixyl synthe’6 peptide complex: manufacturers claim that this boosts the production of 6 major components of the skin including collagen and hyaluronic acid No published evidence available to substantiate this claim yet
• SYN-AKE peptide complex: relaxes muscles to for anti-wrinkle effects
• Relistase peptide complex: slows breakdown of collagen in the skin to maintain skin firmness, according to a study from the manufacturer’s study available No independent studies available on this
• ARGIRELOX peptide complex: also said to reduce wrinkles
The Good About The Ordinary’s “Buffet”
It’s a light weight serum that dries quickly. I did not experience any skin irritation or reactions with The Ordinary’s “Buffet”.
The Bad About The Ordinary’s “Buffet”
This didn’t work for me. It may have made skin slightly more moisturised but I wasn’t convinced that I saw any visible improvement in my lines and wrinkles with using The Ordinary’s “Buffet”.
My Verdict on The Ordinary’s “Buffet”
The Ordinary’s “Buffet” felt like a generic moisturiser on my skin. There were not visible improvements in my wrinkles or skin firmness with this product. I was a little disappointed with the lacklustre results of this product. Will be sticking to my other anti-aging actives.
You can read the rest of my review of The Ordinary’s products in The Ordinary Skincare Review and Ingredients Decoded and my interview with DECIEM CEO in Nicola Kilner, DECIEM CEO, on Disrupting Beauty Trends with The Ordinary and NIOD.
Are peptides another hype that beauty companies are riding on? In my opinion, the data on peptides in skincare is lacking; most of the theoretical benefits of peptides have not been shown in large, randomised controlled human trials. The efficacy of peptides is also limited by their poor uptake in the skin; although new delivery systems are being developed to overcome this challenge.
Personally, I’d skip peptides in favour of well studied, tried and proven anti-ageing ingredients such as retinoids and vitamin C. Having tried a few peptide serums before; I was not convinced of any visible benefits or improvements.
Have you tried any peptide beauty products? What is your take on this ingredient?
1. Topical peptides as cosmeceuticals. Pai et al. Indian J Dermatol Venereol Leprol. Jan-Feb 2017;83(1):9-18.
2. Peptides as Active Ingredients: A Challenge for Cosmeceutical Industry. Ledwon et al. Chem Biodivers. 2021 Feb;18(2):e2000833.
3. Cosmeceuticals: peptides, proteins, and growth factors. Hadmed and Castillo. J Cosmet Dermatol. 2016 Dec;15(4):514-519.