What is Hyaluronic Acid and what are HA benefits?

What is HA? Hyaluronic acid (HA) is a polysaccharide found naturally in our skin.  It is an important component of the extracellular matrix of the dermis (middle layer of skin) where it interfaces with collagen and elastin fibers to help keep the skin smooth, plump and hydrated.  It is also involved in a number of other biological processes such as wound healing, tissue regeneration/repair, and immune response to name a few. From a topical application perspective, HA is a powerful humectant and can draw moisture from the air to increase hydration of the epidermis (outer layer of skin) to make skin look fresh, dewy and bouncy.

Interesting Facts: 1. Water accounts for about 55% to 60% of human body weight.

2. The skin of an average adult weighs about 9 pounds (~4 kg) of which about 64% is water.

3. HA can hold up to 1000 times of its weight in water, a property which makes HA extremely effective in keeping our skin moist and our joints lubricated. It’s no surprise that it’s such a wonderful ingredient! 

4. The average human body contains about 15 grams of HA and 50% of that HA resides in the skin.  The turnover rate of HA in the body is high.  About one-third of it undergoes degradation and replacement with new material each day. In the skin, the half-life (time for 50% degradation to occur) of HA is less than a day.  The degradation of HA can be accelerated by external factors such as exposure to free radicals and ultraviolet radiation - so when you are out in sun, don’t forget to put on your sunscreen!

Benefits of Hyaluronic Acid

Hyaluronic Acid's Anti-Aging Benefits

Human skin aging is a complex biological process, and is the result of two biologically independent processes – Intrinsic aging andextrinsic aging. Intrinsic or innate aging is an unavoidable process which affects the skin in the same pattern as it affects all internal organs. It is caused by hormonal and other naturally occurring physiological changes that negatively impact skin rejuvenation and gives rise to increased dryness, loss of elasticity, and skin wrinkling.3 Extrinsic aging is the result of exposure to external and somewhat controllable factors such as sunlight (photo-aging), pollution and cigarette use. Associated with skin aging is reduced skin hydration. As we age, the production of both collagen and HA decline.  With less HA, there is less bound water to help maintain the skin’s supporting structures and wrinkles become more pronounced. Since most of the loss of HA in the skin occurs in the epidermis, topical application of HA can be especially advantageous as it can draw more moisture into the skin surface to make it look and feel more plump, elastic and radiant. Exposure to the sun and other oxidative environmental stressors further weaken the skin’s defenses thereby accelerating the aging process and moisture loss. With the topical application of HA, more moisture can be returned to the skin as HA draws in moisture from the air. It is an ideal complement to sunscreen to help protect and nourish your skin.  Who should use hyaluronic acid? HA is an inert ingredient and in aqueous solution with appropriate microorganism protection, is very stable.  It can be used with most other ingredients and, at the properly selected molecular weight range, will not cause irritation or an allergic skin reaction. It is suitable for all skin types. Individuals with dry and/or more mature skin can benefit the most from using HA topically.

If you have sensitive skin, don’t be swayed away from using HA because the “acid” descriptor in its name.  HA is very gentle on the skin. If you do experience any side effects from a HA-containing product, see a doctor as it could be due to another ingredient in the product. As with any new product, conduct a patch test to be 100% sure that you are not allergic to it. Hyaluronic Acid's Anti-Aging Benefits HA’s exceptional ability to bind moisture is an important factor to consider when selecting a skincare product as you age. The ability of our skin to hold onto water diminishes as we get older. The result is a visible loss of firmness, pliability, and suppleness (hello, wrinkles).The hydrating properties of HA can help reverse these signs of aging.  In addition, studies show that HA also has anti-oxidant and other skin-replenishing properties. Simply put, with its multi-tasking capabilities, HA is the one must-have ingredient to be included in your anti-aging skin care regimen! As always, don’t forget to supplement your use of HA with a broad-spectrum sunscreen whenever you will be exposed to the sun. 

Is Hyaluronic Acid Safe?  Of course it is safe! It is even approved by the FDA for use in eye care products to treat dry eyes. Caution: Only use eye treatment products and not any skincare product in the eyes. HA can be used every day. Unlike some other “acid” ingredients, it will not strip the outer layer of your skin but instead gently hydrate it leaving it looking more supple and feeling smoother.

Hyaluronic acid pH and key factors in skin absorption The degradation of HA in aqueous solutions has been studied and was found to occur under highly acidic or highly alkaline conditions.Specifically, degradation was observed at pH values < 4 or > 11.  As a quick refresher, a pH value below 7 is considered acidic while a value above 7 is considered alkaline.  Water with a pH value of 7 is classified as neutral.  Now back to the relevance of the study on skincare. Skincare products are typically formulated to match the normal skin pH range of 4.5 to 5.5.  Since HA has been shown to be stable in this range, degradation of HA does not have to be a concern, provided, of course, that the formula incorporates preservative protection from sugar-loving microorganisms.

The molecular weight of HA is a key factor in determining the extent of absorption into the skin. HA is naturally present in our body in a molecular weight range of 4,000 to 8,000,000 Daltons. Studies have shown that HA is the most beneficial in skincare products when it is between 50,000 to 1,000,000 Daltons (50 – 1,000 kDa). This range seems to be the most effective to support the skin in maintaining its moisture and elasticity. Although studies have shown that HA with a molecular weight less than 50,000 results in deeper penetration into the skin, inflammatory responses are initiated with the smaller-sized HA molecules. So the bottom line is to buy an HA product that has a combination of HA’s so that the  desired size spectrum is obtained. Can you pair Hyaluronic acid with vitamin C, niacinamide or Retinols? Most definitely.  HA works well to partner with many other ingredients including vitamin C, niacinamide and retinols.  With retinols, the hydrating and soothing benefits of HA are a great compliment to retinols which are known to cause dryness and irritation.

What to look for in HA serum: Look for a serum with the following features:

1. Contains a minimum of 0.5% HA and a maximum of 2% to keep your skin hydrated for the entire day.

2. Has a pH range between 4 to 6 so that the skin’s normal pH is not disrupted.

3. Is formulated with HA that has a molecular weight range of 50,000 to 1 million Daltons to optimize the hydration benefits on the skin surface while minimizing the possibility of an inflammatory response.

4. Is packaged in an opaque container to minimize degradation from ultraviolet light.

It is one of the best naturally occurring ingredient in the body, produced by the body to take of the body. What more do you want from it – Thoughts?