Maintaining water content in the skin is crucial to both mechanical and physical properties of the skin including elasticity, strength, desquamation, enzyme function, and skin barrier function. Hydration can be supplemented by topical application of cosmetic products containing hygroscopic or humectant ingredients. One of the most well known ingredients used in cosmetics to rehydrate and plump the skin is Hyaluronic Acid (HA). However, Polyglutamic Acid (PGA) is a trending humectant that quenches skin dryness and provides additional skin benefits based on molecular weight, similar to Hyaluronic Acid. So between these two polymeric moisturizing acids, which is right for you?
What Type Of Acid Is Hyaluronic Acid?
Hyaluronic Acid (HA) occurs naturally in all vertebrate tissues and throughout the body in various connective tissues, synovial joint fluids, and in varying amounts in the skin. It is in the skin that the body holds the primary reservoir of HA — up to 50% of the total. Because of its unique rheological, viscoelastic and hygroscopic properties, HA plays a pivotal role in protecting, stabilizing, and reinforcing skin at the cellular level. Hyaluronic Acid, along with collagen, elastin, and essential lipids form the primary elements of the human skin matrix.
Synthetic hyaluronic acid is a glycosaminoglycan polymer produced through fermentation that functions as a humectant and film former in topical skincare. The biological effect of hyaluronic acid depends on its molecular weight. In order to penetrate the skin, hyaluronic acid needs to be hydrolyzed, or chopped into smaller fragments, and these smaller fragments have different skin benefits than high molecular weight hyaluronic acid that remains on the surface of the skin. Its skin hydrating properties are independent of molecular weight attracting water to whatever layers of the skin it resides but low molecular weight hyaluronic acid has wrinkle reduction benefits due to enhanced penetration. It can also help rejuvenate the skin through its antioxidant properties.
What Type Of Skin Is Hyaluronic Acid Best For?
While all skin types can benefit from hydration, dry skin, mature skin, and photodamaged skin can benefit from hyaluronic acid depending on the molecular size used in a cosmetic product. For skin hydration and barrier support a high molecular weight HA can be used. If fine lines, wrinkles, and reduced elasticity are the skin concerns then using a low molecular HA is beneficial. Some individuals can experience sensitivity or irritation to topical hyaluronic acid so those with sensitive skin should patch test before use.
What Type Of Acid Is Polyglutamic Acid?
Unlike HA which is a glycosaminoglycan and therefore a sugar based polymer, Polyglutamic Acid (PGA) is a polypeptide made up of repeating units of amino acid. Unlike HA, PGA is not native to the skin and is applied topically via cosmetic products. PGA is produced via fermentation of L-glutamic acid with bacillus subtilis and available at both high and low molecular weights for intense skin hydration. Polyglutamic Acid (PGA), like HA, is a non-exfoliating, safe biodegradable multifunctional biopolymer designed to enhance skin moisturization and provide additional skin benefits. Both ingredients can rehydrate dry skin as well as enhance the bioavailability and permeation of the skin allowing other ingredients to work more efficiently when applied topically. Because they function as humectant film formers their skin benefits can be seen quickly after application unlike some cosmetic ingredients that rely solely on a biological mechanism and therefore require weeks to see skin benefits.
PGA has proven to be a better moisturizer than that of hyaluronic acid due to its larger molecular size, restoring skin elasticity, plumping the skin, and smoothing skin wrinkles. It can also protect the skin against external aggressions and provide a soothing response for minor skin irritations. A unique characteristic of PGA is its ability to increase the skin’s production of Natural Moisturizing Factors (NMF). The stratum corneum is composed of around 10% NMF which keeps the skin elastic, supple, and hydrated. These critical humectant molecules help skin cells retain and regulate moisture. PGA not only draws water to the skin where it is needed but helps increase the skin’s own moisture homeostasis giving it both a functional and biological benefit. Through hydration, PGA helps skin appear smoother, more radiant, less textured, and healthier.
What Type Of Skin Is Polyglutamic Acid Best For?
Polyglutamic acid is generally well tolerated by all skin types making it a great hydrator for all. PGA is especially beneficial to those with dry skin because not only does it provide immediate skin hydration by drawing water molecules to the skin, it can increase the skin’s NMF. Our Multi-Quench Plumping Hydration Serum contains 1% pure PGA and a 3% PGA complex with two different molecular weights. The low molecular weight (70-100 kDa) PGA penetrates below the skin surface and can help even skin tone and reduce the appearance of hyperpigmentation. The high molecular weight PGA (2600 kDa) forms a flexible film on the surface of the skin to enhance moisture binding while increasing the skin’s NMF.
By not only drawing water to the stratum corneum but enhancing skin’s own hydration system, PGA can restore skin to a more supple, elastic, and plumped state. Hydrated skin appears more radiant because there is less flaking or texture so the light reflects better off the skin. Wrinkles and fine lines are also less pronounced as skin is more hydrated, offering an immediate visual improvement.
Is Hyaluronic Acid Or Polyglutamic Acid Better For Dry Skin?
Both hyaluronic acid and polyglutamic acid offer immediate and noticeable skin hydration but polyglutamic acid can further improve dry skin by aiding in the skin’s natural production of NMF. Polyglutamic acid and hyaluronic acid can even be used together or layered for further hydration and skin plumping as neither of these materials has known compatibility issues. They are both safe to use twice daily.
The synergy of all ingredients in a formula are also key factors to maximum skin benefits. Ingredients in a formula don’t work independently and ingredient percentages can’t tell you possible synergy that can occur. Sometimes the whole is more than the sum of its parts and a combination of ingredients provides better results than predicted if each ingredient were used independently. This phenomenon can’t be explained by an ingredient deck or percentages and in the case of HA and PGA, the molecular weights of the material are key to determining how well it performs on skin.
DISCLAIMER: All skin care articles are intended to help educate on specific ingredients and skin care topics. Our articles are written to be informative and informational. Any reference to a specific patient experience is not a medical suggestion for treatment. Please note that any Prequel products with referenced ingredients are formulated for Cosmetic Use Only and NOT intended as replacements for physician advice and/or pharmaceutical product recommendations.
