Hyaluronic acid (HA) is one of the darlings of skincare because of its proven ability to effectively hydrate the skin. This humectant is a naturally occurring sugar molecule in the skin that binds to water, provides hydration and helps “plump” up the skin giving it the look of “fullness” – think of a dewy, natural glow effect.
Although HA can be found naturally in almost every cell in the body, it is found in the greatest concentrations (almost 50%) in the skin.1 It is found in both the deep underlying dermis, as well as the top layers of the epidermis. HA attracts and binds water to the skin. It keeps the skin looking smooth, youthful and vibrant. Young skin is smooth and elastic and contains large amounts of HA. With age, the ability of skin to produce HA decreases; furthermore, HA has a short “shelf-life” in the skin, naturally turning over or degrading within 24 hours, this time-frame slows down with age resulting in skin that appears rough, dry and flaky.
Why size matters when it comes to HA
In addition to being an important ingredient in topical skincare products, HA is also the key ingredient in injectable fillers that Dermatologists, Plastic Surgeons, and other licensed medical professionals use to provide facial volume and smooth deeper expression lines for their patients.
An important distinction between injectable and topical hyaluronic acids is size. The injectable hyaluronic acids do vary in size, but typically have a higher molecular weight (they can be big – 2 million Daltons or more!). Further, many HA fillers are “cross-linked” or joined together to enable longer-lasting volume in the skin, making them even larger and only deliverable by injection.
For the best outcomes with injectable fillers, injectors often reach for a combination of filler products to deliver different sized HA to targeted areas of the skin (deep wrinkles versus superficial ones, for example).
Anything greater than 500 Daltons is likely to sit on top of the skin if not intentionally delivered to its target.2 However, with targeted technologies, HA can be delivered topically to intended targets in the surface of the skin for supple, glowing and resilient skin.
And while topical skincare products will never be able to deliver the results of injectable procedures conducted by trained professionals, topicals can take inspiration from the multi-faceted approach, combining multiple sizes of HA to plump and hydrate the different layers of the skin. Pairing injectable HA with topical HA can lead to beautiful, complimentary results for improved patient outcomes.
Topical HA is suitable, well-tolerated and can be beneficial for most skin types, not just aging skin.
REFERENCES FOR THIS INFORMATION:
1 Brown MB, Jones SA. Hyaluronic acid: a unique topical vehicle for the localized delivery of drugs to the skin. JEADV 2 005; 19:308-318.
2 Bos JD, Meinardi MM. The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Exp Dermatol. 2000; 9(3):165-9.