HISTORY
Hyaluronic acid, discovered in 1934 by Karl Meyer and John Palmer from cow eye vitreous humor, derives its name from the Greek word "hyalos," meaning glass, due to its clear appearance. Initially utilized for its lubricating and hydrating properties in medical applications like eye surgeries, HA gained medical prominence throughout the 20th century, notably in the 1970s as an osteoarthritis treatment via joint injections.
SCIENCE
Hyaluronic acid (HA) exists in various molecular weights, significantly influencing its function and benefits. High molecular weight HA (HMW-HA), ranging from 500k to 4M Daltons, is predominantly found in our skin, acting as a potent hydrator capable of binding up to 1,000 times its weight in water. This makes it an excellent ingredient for surface hydration and forming a protective barrier, though it likely does not penetrate deeply into the skin. HMW-HA also enhances skin elasticity, reduces inflammation, and helps repair the skin barrier.
Conversely, low molecular weight HA (LMW-HA), which is 500k Daltons and below, serves a different role. It often forms at injury sites, acting as a pro-inflammatory signal to initiate repair processes. When applied topically, its penetration is limited, primarily affecting the upper skin layers. Despite concerns about its potential pro-inflammatory effects, studies show that LMW-HA, particularly in the 50kDa and up range, can aid in skin repair and improve conditions like rosacea and seborrheic dermatitis.
A study by Evonik revealed that while ultra-low molecular weight HA (below 50kDa) might induce inflammatory signals, LMW-HA in the 50kDa range effectively plumps up wrinkles without causing inflammation. Interestingly, another study suggested that a 10kDa HA version offers better antioxidant activity and sun protection compared to higher molecular weight versions.
In summary, while ultra-low molecular weight HA might raise concerns, normal LMW-HA appears safe and beneficial for most skincare applications. The versatile nature of HA, with its varying molecular weights, underscores its importance in skincare, offering hydration, protection, and repair.
REFERENCES
- Taieb, M., Gay, C., Sebban, S., & Secnazi, P. (2011). Hyaluronic acid plus mannitol treatment for improved skin hydration and elasticity. Journal of Cosmetic Dermatology, 11, 87–92.
- Mejkalova, D., Huerta-Angeles, G., & Ehlova, T. (2015). Hyaluronan (hyaluronic acid) a natural moisturizer for skin care. Harry's, 2(Part 4.1.3), 9th ed. Contipro Pharma.
- Corrêa, M.E.A.B., dos Santos Haupenthal, D.P., Mendes, C., et al. (2020). Effects of Percutaneous Collagen Induction Therapy Associated with Hyaluronic Acid on Inflammatory Response, Oxidative Stress, and Collagen Production. Inflammation, 43, 2232–2244.
