In this article:
What are amino acids?
How amino acids benefit skin
Do amino acids increase collagen?
Do amino acids tighten skin?
The best amino acids for skin
How to use amino acids for skin
Can you use amino acids daily?
Are amino acids safe for skin?
How amino acids work with peptides
The term “amino acids” often dots the ingredient lists of moisturisers and serums claiming to assist with hydration, soothing and the visible improvement of skin health.
If you haven't looked deeply into this group of impressive ingredients (we don’t blame you, skin care ingredients can be intimidating!), here’s the quick rundown: Amino acids are the building blocks of both peptides and proteins, and each has a specific role in skin care. Amino acids maintain skin’s hydration, texture, resilience and contribute to an overall supple, healthy appearance.
It’s easy to get overwhelmed at the sheer complexity and number of amino acids, so we’re going to dig into these amazing aminos, explain how they work, detail their benefits for skin and walk you through how you can incorporate them into your skin care routine.
What are amino acids?
Amino acids are organic, naturally occurring compounds. As we mentioned above, they’re the building blocks of proteins and peptides, so it’s not a stretch to say that amino acids are indispensable for our skin and our body (1).
There are many amino acids, but most scientists agree that there are 20 that are important to our health, divided into two types: essential and non-essential (2). The “non-essential” term doesn’t mean that those amino acids aren’t important; rather, it means that your body can make them on its own, so it’s not “essential” for you to get them from foods or supplements.
“Essential” amino acids, on the other hand, are essential because they must be obtained from foods or supplements; a deficiency in even one of them can result in health problems.
There are nine essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. The best food sources of these amino acids include animal protein (seafood, beef, poultry), followed by animal by-products such as eggs and dairy. Vegan sources of essential amino acids include quinoa and soy/tofu. Beans and nuts also provide some amino acids, but not all the essentials.
The 11 non-essential amino acids the body can make on its own include alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine and tyrosine. Several of these are also known as “conditional” amino acids, meaning they’re made by the body, but only under certain conditions, such as when we're under stress or ill.
Each amino acid plays a vital role in maintaining our health as well as the appearance of our skin. But just how do amino acids work on and within skin?
How amino acids benefit skin
Amino acids are naturally present in skin, as part of what’s called our natural moisturising factors (NMFs) (3). Within skin’s uppermost layers, amino acids work as conductors, orchestrating an incredibly complex “concert” that allows our skin to thrive and to stay hydrated.
One of the ways they do this is by working in harmony with aquaporins (the body’s water transport system) to move moisture throughout skin. Because of this, the primary benefits of amino acids for skin are assistance in the maintenance of skin’s smoothness and hydration, something they also do when applied via skin care products (4).
There also are more surprising benefits of these small, but potent, skin care heroes: Some amino acids work as antioxidants; however, most of them are believed to play an even greater role by helping skin create more of its own antioxidants, such as glutathione. Topically applied amino acids are good for skin, helping to strengthen its natural defence system. This benefit means skin will be less likely to show signs of ageing from environmental damage (5).
Interestingly, research has shown that synthetic amino acids often have greater hydrating ability than animal- or plant-derived amino acids. Because many amino acids are animal-derived, this is encouraging news if you prefer to avoid such ingredients, as we do.
Do amino acids increase collagen?
When amino acids form long or short chains and create peptides, research shows they can help support collagen production (6). Research has also suggested that lysine, an amino acid, can help bolster the production of necessary elements that keep skin looking and feeling firm (7).
On their own, the main benefits of amino acids for anti-ageing include assisting in protecting skin from pro-ageing environmental factors and smoothing the look of fine lines and wrinkles via hydration.
Do amino acids tighten skin?
Amino acids, as a skin care ingredient group, aren’t inherent skin-tighteners. Much like how amino acids help support collagen production when they form peptides, amino acids can help promote a firmer appearance when in the form of peptides. To learn more about which peptides are best for fortifying skin’s architecture, read our guide to peptides for skin.
However, certain amino acids, like lysine and proline can help promote a sturdier, more youthful appearance.
The best amino acids for skin
Although all the amino acids we mentioned play a role in creating and maintaining smooth, healthy, younger-looking skin, a few also have more specialised roles, which make them even more desirable to see in skin care products:
- Arginine plays a role in repairing visible skin damage.
- Histidine has antioxidant ability and can soothe skin.
- Methionine neutralises damaging substances before they can harm skin.
- Lysine benefits for skin include helping visibly firm skin’s surface by reinforcing its supportive elements.
- Proline, leucine, and glycine diminish the look of fine lines and wrinkles.
How to use amino acids for skin
Using amino acids in your skin care routine is as easy as seeking out a moisturiser, serum or eye cream that includes these ingredients. Amino acids are also a great addition to sunscreens, where they help fight environmental damage and actively soothe.
For best results, this group of ingredients is best suited for leave-on product formats (those you don’t wash off) since prolonged contact with skin results in longer-lasting benefits.
Remember, a product might not list “amino acids” on its ingredient list; instead, it’ll use the individual amino acids’ name included in the formula, like arginine or lysine.
Skin tip: If you’re looking for extra hydration try using a hyaluronic acid and amino acid serum.
Although topical application is our focus, the most common way to benefit from amino acids is through incorporating them into your diet (8).
Can you use amino acids daily?
Yes, you can use amino acids daily. Amino acids are suited for all skin types and can be especially beneficial for dry and sensitive skin types. Because of their gentle nature, you can incorporate them into both your daytime and nighttime routines, and it’s fine if aminos are present in multiple products (you really can’t overdo it).
Amino acids may be applied at the same time as ingredients such as retinoids, vitamin C and niacinamide, among others. There are no contraindications with this ingredient group.
Are amino acids safe for skin?
The Cosmetic Ingredient Review Expert Panel deemed amino acids safe for skin as used in current practices and concentrations (9).
When applied topically in a cream or serum, amino acids have no reported side effects. Seeing as they’re a natural part of skin and are necessary for both skin and overall health, this makes sense.
How amino acids work with peptides
All amino acids included in skin care products work in combination with other ingredients that are also part of skin’s NMFs, including our favourites glycerine, ceramides, various peptides and hyaluronic acid. Amino acids work particularly well with peptides, because, if you recall, peptides are chains of amino acids.
Amino acids are truly versatile ingredients that complement other beneficial skin care ingredients, from antioxidants to plant extracts to omega fatty acids. Without question, topically applied amino acids improve all skin types, and can benefit all ages, especially if your goal is hydration or to prevent or diminish signs of ageing.
Learn more about skin care ingredients.
References for this information:
- Annals of Translational Medicine, December 2018, pages 1–10
- Biochemical Journal, June 2017, pages 1,935-1,963
- International Journal of Molecular Sciences, April 2022, pages 1–11
- Journal of Cosmetic Dermatology, July 2022, pages 3,046-3,052
- Marine Drugs, April 2019, pages 1–18
- Cosmetics, May 2017, pages 1–14
- Experimental Dermatology, January 2021, pages 38-49
- Journal of Clinical Biochemistry and Nutrition, July 2019, pages 52-58
- International Journal of Toxicology, Nov-Dec 2013, pages 41S-64S
