Peptides and retinol are two of the biggest players in the skin space with much of their celebrity status coming from their use in the “anti-aging” industry. But how promising is each active ingredient for skin longevity and which one – if not both – should you integrate into your skin health routine?

Wondering, what is a peptide? Or, what do retinoids do? Let’s start with the basics:Peptides are small biological molecules containing two or more amino acids arranged in a chain-like fashion. Peptides that are linked together naturally become arranged in complex structures to form proteins (aka “polypeptides”), which are the molecules responsible for nearly every cell function. Collagen is the most abundant protein in the human body and is vital to skin health and longevity. The dermis (middle) layer of the skin is particularly important for skin longevity as this is where collagen-producing fibroblast cells reside. It’s widely accepted that collagen synthesis and subsequent collagen levels in the skin decrease with age, leading to changes in skin, such as fragility, increased fine lines and wrinkles, sagging, and loss of elasticity ¹.
Peptide research and discovery is an exciting space for cutting-edge skincare. But, how to use peptides in skin care is the leading question. As direct supplementation of collagen to skin is difficult, skincare science has cleverly developed peptides that can promote collagen synthesis on a genetic level to rejuvenate skin from the inside out.
Here are a few big players that are gaining attention for their collagen-boosting properties.

• Copper peptides are a type of carrier peptide that work together with antioxidant enzymes in the skin to protect collagen. This active ingredient also fights reactive oxygen species that can wreak havoc on other important molecules like DNA ².
• Palmitoyl pentapeptide-4 is another popular peptide to hit the market. Professionally known as Matrixyl, this ingredient has been shown to reduce wrinkles and increase skin elasticity in several biologically-relevant experiments ³.
• OS-01 is a novel peptide that was originally developed in the OneSkin lab. This peptide is the first of its kind to reduce the onset of cellular senescence (which would otherwise result in the accumulation of “zombie” cells directly shown to cause skin damage and aging) to rejuvenate skin. The OS-01 peptide has been scientifically proven to increase the activity of genes responsible for collagen, hyaluronic acid, and elastin production. It also decreases the activity of genes associated with aging and inflammation.

Retinol is a modified form of vitamin A, also known as retinoic acid. Vitamin A is crucial for central nervous system and immune system homeostasis, and even has antioxidant properties ⁴. Retinoids can be broadly found on ingredients list as tretinoin, retinol, retinal, retinyl palmitate, or retinyl acetate – and depending on their concentration – they may induce negative side effects on your skin. Retinoids work by stimulating skin cell turnover and boosting collagen synthesis. By using retinol, dead skin cells at the surface of the skin are replaced with younger cells. Unfortunately, this rapid cell turnover can weaken the skin barrier temporarily after each use, leaving your skin and body vulnerable for a brief period of time, so proper skin care following use of retinol is critical for allowing the skin barrier to recover.
Some stronger retinoids are prescription strength; only given by dermatologists to treat more stubborn skin conditions such as severe acne, fine lines, and/or dark spots to even out skin tone and improve overall skin texture. However, retinoid use can also (commonly) result in: skin irritation, skin dryness, skin sensitivity, skin flaking, and increased sensitivity to the sun. Given retinol’s harsh effects, certain skin types (especially sensitive skin) may not work well with any vitamin A derivatives. Additionally, you should avoid using retinol products if your skin is consistently exposed to the sun.
Peptides, on the other hand, are typically suitable for any skin type.The benefits of peptides are remarkably similar to those of retinol in terms of collagen synthesis and skin rejuvenation, however, peptides typically don’t induce negative side effects. Therefore, if you want the rejuvenation benefits of retinol without the negative side effects, a peptide moisturizer may be your answer.OneSkin’s proprietary peptide, OS-01, has been extensively studied against retinol and found to induce similar benefits with none of the harsh side effects. In fact, when tested against retinol on skin equivalents in the OneSkin lab, the OS-01 peptide increased the activity of genes associated with collagen and hyaluronic acid similar to the levels induced by retinol. Perhaps more important, retinol significantly increased genes associated with aging and inflammation, while the OS-01 peptide reliably decreased the activity of those same genes.
If you are concerned about the side effects that come with retinol use and their impact on your long-term skin health, but still want the rejuvenation benefits of improved collagen production, consider using a peptide approach with OneSkin’s OS-01 Topical Supplements.In terms of comparing peptides vs retinol, OS-01 and retinol are neck and neck at promoting the production of collagen and hyaluronic acid in skin, two key factors in hindering the development of visible fine lines and wrinkles. The other large factor to consider when evaluating an ingredient’s ability to diminish fine lines and wrinkles is its ability to increase epidermal thickness of the skin. Like crinkled paper, the thicker the skin, the less visible the fine lines and wrinkle creases will be. By comparing epidermal thickness of skin models in the lab when exposed to the OS-01 peptide vs retinol, retinol caused skin thickness to decrease, while the OS-01 peptide reliably increased skin thickness. Therefore, the OS-01 peptide is expected to be superior at diminishing fine lines and wrinkles.
When it comes to addressing peptides in general for their ability to decrease fine lines and wrinkle creases, there’s no clear answer. That’s because peptides are a broad class of molecules and each peptide has a different mechanism of action in the skin. Before assuming that a peptide-based product will improve fine lines and wrinkles, be sure to confirm that the peptide has been scientifically validated for its effects on skin health markers.So who wins in the skin longevity showdown? The jury is still out, but the scientists at OneSkin caution against using retinol for improved skin longevity.
Retinol can quickly degrade the skin barrier and increase the activity of genes associated with inflammation and aging ⁸, therefore using concentrated retinol or using retinol over an extended period of time has a high potential to compromise your long-term skin health, thereby diminishing your skin’s longevity. In contrast, OneSkin’s OS-01 peptide reliability improves internal and external skin health markers, making skin healthier from the inside out. Additionally, the OS-01 peptide is the first peptide proven to decrease skin’s biological age, thereby extending the length of time that skin is healthy and functional (aka your skinspan). That means that the OS-01 peptide has been scientifically proven to extend skin’s longevity.Both retinol and peptides have been shown to fight the signs of skin aging. But choosing one skin care ingredient over the other depends on what skin concern you are trying to treat.
Peptides still have a ways to go in terms of testing en masse compared to numerous, published scientific studies performed with retinol. That being said, peptides are more skin-friendly than retinol by a long shot, due to their more moisturizing nature. This can make them more amenable to everyday use. On the other hand, retinol can be quite effective (yet harsh!) at treating acne, evening skin tone, and lessening the appearance of dark spots. As a rule of thumb, retinol should not be used every day even after skin has been introduced to it, as consistent retinol use of even low concentrations causes extreme sun sensitivity and can weaken the skin barrier.A peptide-based product that has been scientifically proven to improve skin health markers (like epidermal thickness and hydration), such as OS-01’s Topical Supplements, will pair well with retinol as it can counteract some of retinol’s negative side effects.
Be cautioned that by pairing retinol directly with a peptide product, the harsh side effects of retinol may be heightened due to its increased penetration in the skin ^5,6,7. A good way to get around this potential interaction is to alternate your use of retinol and peptide-based products.
The moral of the story? Though retinol and peptide-based products are effective at improving collagen and hyaluronic acid production to produce rejuvenating effects, retinol may compromise your skin’s health in the long-term. Peptide-based products like OneSkin’s OS-01 Topical Supplements extend internal and external skin health markers for improved skin health and longevity. Whether you choose to use retinol, peptides, or both, always be sure to consult a dermatologist if you experience negative side effects and try to ensure that the active ingredients within your topical skin care products are scientifically validated for their rejuvenation effects on skin.

• Age-associated decrease in collagen levels in the skin causes visible signs of aging, including loss of elasticity and fine lines/wrinkles.
• Peptides’ anti-aging benefits come from their ability to promote collagen synthesis, among other benefits depending on the peptide
• Retinol improves collagen synthesis in skin, but often at the expense of skin dryness, inflammation, and sun sensitivity.
• Peptides are generally more gentle and moisturizing than retinol and therefore a better choice for those with a more sensitive skin type.
• The OS-01 peptide, which powers OneSkin’s OS-01 Topical Supplements, is the first peptide scientifically proven to reduce skin’s biological age, thereby extending skin longevity. It increases the activity of genes associated with collagen and hyaluronic acid to similar levels as retinol while enhancing other skin health markers that retinol degrades, such as epidermal thickness.

1. https://www.tandfonline.com/doi/full/10.1080/15569520701622951
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6073405/
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6832239/
4. https://pubmed.ncbi.nlm.nih.gov/9478051/
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5108505/
6. https://www.mdpi.com/2079-9284/4/2/16/pdf
7. https://onlinelibrary.wiley.com/doi/10.1002/adhm.201500634
8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2699641/