What is Hyaluronic Acid?

Hyaluronic acid is the main constituent of the most used biodegradable temporary dermal fillers. Hyaluronic acid (HA), a sugar-based compound known as hyaluronan, is a clear, viscous liquid and a natural component of skin, bones, cartilage and connective tissues. HA is involved in many vital processes, including cell nutrition, cell signalling, wound reparation, tissue regeneration, fibroblast and collagen stimulation.

As a significant component of skin, it is involved in repairing tissue, is used as a stimulating agent for collagen synthesis and is a common ingredient in skin-care products. It is believed to be an essential factor in fighting the ageing process.

The average 70 kg (150 lb) person has approximately 15 grams of hyaluronan, with 50% of the human body HA being found in the skin.

The most crucial property of HA is its high water-binding capacity (hydrophilic), which gives the skin its moisture, elasticity and resilience. However, the skin’s HA content decreases with time due to various physiological and environmental effects, including the natural ageing process and UV exposure. The skin loses moisture and becomes less elastic, resulting in visible lines and wrinkles.

The sources of HA used in fillers are either bacteria (i.e., produced by non-pathogenic bacterial fermentation) or avian origin (i.e., derived from rooster combs). HA obtained from these sources is thoroughly sterilised during the manufacturing process.

A recently proven additional benefit of HA fillers is their secondary tissue-regeneration effect. Due to its strong hydrophilic properties, HA injection results in temporary compensation for the volume loss and biological improvement by supplying the tissues with additional fluids, which is why HA results in continuous clinical improvement over time, even in patients who do not receive further treatments. Furthermore, recent data have highlighted that HA fillers also stimulate long-term collagen production.