Text by: Christal Leung
Topical and injection Hyaluronic Acid or HA has become the gold standard in skin rejuvenation, prompting dermatologists, beauticians, beauty bloggers, and users worldwide to endorse and rave about its lasting results.
But what is HA? It’s been called “nature’s ideal moisturizer” – but does it really live up to the hype?
What is Hyaluronic Acid?
Dr. Jessica Krant, dermatologist and Assistant Clinical Professor of Dermatology at the State University of New York’s Downstate Medical Center, described Hyaluronic Acid or hyaluronan as “the body’s lubricant molecule.”
She said, “It is basically a very big and complex sugar-related molecule called a glycosaminoglycan that is found naturally throughout the body and works in many different ways to keep us healthy and active. It’s involved in the health and function of skin, joints, and the immune system.”
In cosmetology, HA is commonly used in cosmetic fillers which are injected under the surface of the skin to replace lost volume and fill deep folds. It is also gaining popularity as an anti-aging ingredient in topical products, Krant said.
This biopolymer naturally occurs in the human body and belongs to a family of connective tissues that are particularly beneficial to joints and skin, but is also widely found in epithelial, neural, and connective tissues.
HA is produced by skin cells that are responsible for tissue regeneration in the dermis – an inner layer of the skin. This means that HA provides structural support by serving as a cushion against other cellular compounds. It also protects the skin from micro-organisms, and promotes tissue reparation and healing.
It is part of a major component in our skin dermal layer, known as glycosaminoglycan (GAGs). GAGs are responsible for binding water to support the skin’s naturally occurring collagen, thus making the skin smoother and suppler.
Dubbed “nature’s ideal moisturizer,” HA has a chemical structure that allows it to absorb water, up to 1000 times its own molecular weight.
Aging and Hyaluronic Acid Degradation
Everybody produces HA, however, this ability diminishes with age. Along with dermal shrinkage, lower HA levels results in loss of moisture and skin elasticity, which eventually leads to dull, saggy, and yellowish skin.
Skin aging usually begins with the loss of HA. Scientists have long suspected that HA degradation is associated with skin inflammation, oxidation, decelerated metabolism, and the decreased amount of stem cells present in the skin. According to some studies, HA levels start decreasing as early as the age of 18, causing micro-aging in our skin that paves way for the onset of wrinkles, fine lines, crow’s feet, and dryness.
Hyaluronic Acid in Cosmetics
Before the age of Hyaluronic Acid, collagen was widely advertised as the godsend of skin rejuvenation. Contrary to popular belief, external sources of collagen cannot replace the loss of the collagen naturally found in human skin. These external collagen products have a bulky chemical structure and high molecular weight, prohibiting the macro-molecule from reaching the dermis and replenishing depleted collagen s tores. Thus, collagen in skin care formulas only provides a temporary nourishing emollient that literally only goes skin deep.
It wasn’t long before molecular biologists and dermatologists realized that replenishing hyaluronic acid levels in the skin can better reverse the signs of aging. Topical HA formulas and HA injections were soon developed and these products took the market by storm.
Sodium Hyaluronate, or the solid form of HA, is dissolved in water to form the HA solution used in most skin products. This sodium hyaluronate is typically produced through bacterial fermentation. HA can only be extracted from animals, but the process is more expensive and poses animal rights and contamination concerns.
There are two variations of sodium hyaluronate – Low Molecular Weight sodium hyaluronate (LMW, from 5,000-20,000 Daltons) and High Molecular Weight sodium hyaluronate (HMW, ~500,000 Da or more).
HA levels start decreasing as early as the age of 18.
HMW sodium hyaluronate is the larger complex and is known to have anti-inflammatory and skin moisturizing effects. Meanwhile, LMW sodium hyaluronate has higher penetrating power and can better bind surface moisture. These two types of hyaluronate are often used in HA products, whether in injection or topical form.
HA injections allow delivery of the molecules into the deep layers of the skin known as the dermis. These injections can directly restore depleted levels of HA to produce a lifting, firming, and feature-sculpting effect. Skin is instantly plumped as missing spaces are filled with HA, and can restore a youthful appearance around the eyes, face, neck, chest, and any other HA-deprived areas. In this form, HA can be considered an alternative to botox, and its effects usually last from six to eight months.
Topical HA, meanwhile, is used in a variety of serums, creams, and gels. Many high-end cosmetics today incorporate a high concentration of both LMW and HMW HA.
When applied onto the skin surface, HMW HA forms a light protective layer that draws in moisture from the air to produce a visually appealing skin. At the same time, LMW HA seeps into the top layers of the skin to offer deeper hydration.
Clinical trials and researches on the efficacy of topical HA found a direct correlation between HA application and an increase in skin smoothness, hydration, and amelioration of wrinkles under microscopic skin surface analysis. It has also been shown to boost elasticity, soothe inflammation, and balance moisture level.
In its pure water soluble form, HA is hypoallergenic and can be used for maintenance after undergoing invasive procedures such as chemical peeling, laser treatments, and roller treatments.
It can also be used with retinoids and other ingredients that induce drying of the skin for soothing and moisturizing purposes.
A winning HA formula
When choosing a topical HA product, a combination of HMW and LMW HA is best. Some products are also made using high-tech manufacturing processes that enhance the penetrating ability of the acid, ensuring that the HA reaches parts of the skin that really need it.
Avoid HA formulas that contain sulfates, parabens, alcohol, or other ingredients that may be harmful to the skin. These may also counteract the effects of HA.
All in all, HA is a promising and safe skin care ingredient for skin hydration, and as the first line of defense against skin drying.
Thanks to modern day research, this potent ingredient can be produced and refined to enhance delivery of much-needed moisture into our skin.