What are peptides? How did they even come to the idea to use them in cosmetics? In this post you will learn everything about peptides, their positive properties and about challenges that manufacturers face when they are creating and including peptides in cosmetics.
The fact is that we are ageing and so is our skin, the most obvious signs of ageing are seen on face. Wrinkles, redness, hyperpigmentation start to appear. There is also a decrease in collagen fibers and skin moisture. Facial expressions cause wrinkles too. Smokers tend to have more wrinkles around the mouth area, while people who laugh a lot tend to have move wrinkles around their eyes.
What are peptides?
Peptides are compounds that consist of shorter amino acid sequences. There are two types of compounds oligopeptides, that are short peptides and polypeptides that consist of longer sequences. Very long amino acid sequences are typical for proteins (like collagen). Peptides differ from each other by physiological functions, some are peptide hormones, others are antimicrobal,..
We gain peptides with partial hydrolysis from proteins. But here we bump in our first problem. Unfortunately in this process manufacturers have no control how long the peptide will turn out (how many amino acids will it consist of), what chemical structure will it have and whether the chemical composition will be the same in every synthesis. Consequently we don’t know the mechanism of action and how long will the compound last.
Synthetic peptides
They are better, because they have explicit chemical composition. Consequently there are less mistakes when manufacturing, their production is also safer.
Why would we even use peptides in cosmetics?
Because they affect cell receptors and receptors participate in physiological answer.
- Stimuation of collagen synthesis and aid in firmer and thicker skin – ideal ingredient in anti-ageing cosmetics
- Stimulation⁄braking of melanin synthesis – useful in tanning and lightening products
- Anti Inflammatory effect – useful for cosmetics that soothe the skin
Peptides influence homeostase of skin barrier
Applied topically, peptides slow down skin ageing, studies say. On the face there is visible reduce of fine lines, the skin firmness is higher. Peptides take care of skin barrier homeostase.
Examples of peptides used in cosmetics
- Acetyl hexapeptide-8 – two studies that used this peptide topically showed reduce in deepness of wrinkles
- Trifluoroacetyl tripeptide-2 – expresses lifting effect, stimulates collagen production, brakes matrix metalloproteinase and reduces looseness of the skin
- Palmitoleil tripeptide-7 – establishes cell communication and slows down the ageing process. It stops proinflammatory interleukins 6 and 8 (they cause inflammation). Skin inflammation happens for a reason, every time this happens there are consequences on the skin.
In study there was a serum with peptides tested on several women with mildly photoaged skin. None of the testee’s reported about irritation. Women noticed reduced redness in comparison with placebo serum. After 14 days of using the serum with peptides there was an evident change, especially in the under eye area. There was reduce in smiling wrinkles noticed as well. Testee’s reported about much better general look of the skin like smoothness, softness and skin glow.
Why don’t we find peptides in every skin care product?
- Questionable solubility and stability – we don’t know whether our peptide will be durable in the formulation and whether it will keep its biological activity
- Does it penetrate the skin? For the best would it be if we packed them in delivery systems, but this is not as simple as it sounds and we don’t know if they will reach the target area
- Quite expensive – this is quite a problem since we usually don’t want to spend more than 30 EUR for a product
- There are small concentrations needed – which is good right? But there is a bigger chance that the peptide will not last for a long enough time to reach to target area. They will probably decompose (will still have a hydration effect because of the amino acids, but will not stimulate collagen production)
- Safety of this compounds – still questionable, since we don’t know what compounds it forms if it connects with other compounds – risk for unwanted effects
With peptides we target cells that are dermis or subcutis. But as we already know, our skin is designed in a way that ingredients hardly pass upper layers of the skin. Consequently it is hard for peptides to reach deeper layers of the skin and get to the target area.
What can we conclude?
We can use modified peptides to get better stability and effects on the skin (moisture, firmness, softness) and hair. If we mix them with silicones we get ingredients for hair care that increase hair glow and moisture.
We think peptides are an amazing ingredient in cosmetic products. We have to investigate further to find more stable forms and good delivery systems that will enable peptides to travel to the target areas.
