Amino acids are naturally occurring organic compounds that are the building blocks of proteins and peptides. They are essential for our bodies and vital to skin health.
Our skin naturally contains amino acids, which help support the skin barrier. Adding them to your skincare routine can help make your skin firmer, more toned, and hydrated.
Studies conducted to date show that amino acids and their derivatives are useful for reducing the appearance of signs of aging: formulations containing them offer several benefits for maintaining skin elasticity.
Article by Elisa Avalle, founder of LeLang Skin Care and dermocosmetics specialist. Cover image generated with the support of artificial intelligence.
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What are amino acids?
There are twenty amino acids in total. The “non-essential” ones are no less important; in fact, they are amino acids that our bodies can produce on their own, so they do not depend on diet or supplementation.
Essential amino acids, on the other hand, must be obtained through food or supplements: if deficient, they can harm your health. The nine essential amino acids are:
- histidine
- isoleucine
- leucine
- lysine
- methionine
- phenylalanine
- threonine
- tryptophan
- valine
They are found in animal-based foods and soy, or in incomplete amounts in legumes and nuts. The eleven non-essential amino acids, on the other hand, include alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
In the skin, amino acids act as natural moisturizing factors: they take part in processes that help the skin stay hydrated and elastic over time.
The role of amino acids in the skin
Amino acids work in synergy with aquaporins, the proteins that transport water in the body, helping distribute moisture throughout the skin. Their main function is therefore to maintain soft, hydrated skin.
Some specific amino acids also act as antioxidants, while those applied topically help strengthen the skin’s natural defenses against environmental damage.
Research shows that, thanks to their ability to form long or short chains, amino acids can support collagen formation and strengthen the components needed to keep skin firm. They often promote a firmer appearance in the form of peptides, which can strengthen the skin’s architecture.
Although they all play a role in maintaining smooth, healthy skin, some are more specialized than others: arginine plays a crucial role in repairing damage, histidine has antioxidant properties, and lysine helps visibly firm the skin’s surface. Proline, leucine, and glycine, meanwhile, help reduce the appearance of fine lines and wrinkles.
What effects does it have on the skin?
Amino acids hydrate and help retain moisture, giving skin a healthy, plump appearance. By boosting and retaining hydration, they help rebalance pH, thereby helping soothe visible redness.
As the building blocks of all proteins, they are also a key component of natural collagen levels. By supporting its production, they help visibly repair skin from everyday environmental stressors; collagen stimulation also helps firm and smooth the appearance of fine lines and wrinkles.
L’Arginine: the most studied amino acid in cosmetics
Of all the amino acids, arginine has received the most attention from cosmetic research. It is a semi-essential amino acid produced naturally by the body, with a role that goes far beyond hydration.
Its molecular structure allows it to attract and retain water, improving skin hydration and limiting transepidermal water loss. That’s why it is an important part of the Natural Moisturizing Factor, the skin’s natural moisturizing factor. But arginine also works at a deeper level, supporting protein synthesis and therefore the production of collagen, and acting as a precursor to nitric oxide, the molecule that promotes skin microcirculation.
There’s one distinction worth making before you buy anything: arginine taken as a supplement and arginine applied to the face don’t do the same thing, and only the latter is a cosmetic ingredient. The difference, including the mechanisms of action in detail, is explained in arginine for the skin: topical application or oral supplement.
You’ll find it in the Ferulic + HA face serum, where it works in synergy with Hyaluronic Acid at different molecular weights and a stabilized form of Vitamin C, for a combined hydrating, antioxidant, and reparative effect.
FERULIC + HA SERUM Vitamin C and ferulic acid face serum Antioxidant and tone-evening, with dual hyaluronic acid. Helps prevent dark sp... Discover FERULIC + HA SERUM
Frequently asked questions
What do amino acids do for the skin?
They’re part of the skin’s natural moisturizing factor: they help retain water in the stratum corneum and keep skin soft and supple. They’re also the building blocks of peptides and collagen.
What’s the difference between amino acids and peptides?
Peptides are short chains of amino acids. In skincare, individual amino acids mainly help with hydration, while peptides have more specific functions, such as signaling the skin to support collagen production.
Are amino acids suitable for sensitive skin?
Generally, yes: they’re natural components of the skin and are well tolerated. As with any product, if your skin is very reactive, it’s best to introduce one new product at a time.
Is L-arginine applied to the skin the same as a supplement?
No. Cosmetic L-arginine works on the surface to hydrate and support the skin barrier, while arginine taken orally follows different pathways. Only the former is a cosmetic ingredient.
Conclusion: small building blocks, big results
Amino acids aren’t flashy or trendy ingredients, but they’re the foundation of almost everything that keeps skin hydrated, firm, and resilient. Adding them to your routine, on their own or in the form of peptides, means working on the foundations rather than the surface.
As always, consistency makes all the difference: results take time, but they also last longer.
15-Minute Free Consultation with the Founder
Want to find out which active ingredients are best suited to your skin’s needs? Book a free virtual skincare consultation with Elisa Avalle, founder of LeLang: together, we’ll assess your skin type and the most effective routine.
