Sodium Hyaluronate is a substance that naturally occurs in your skin and joint fluid. It is well known as a skin care ingredient and applied topically for its ability to reduce the appearance of fine lines and wrinkles and to plump the skin. Sodium Hyaluronate is a salt form extracted from Hyaluronic Acid. Sodium Hyaluronate is sometimes called Hyaluronic Acid since it is derived from it, so you may see either title on skin care labels. It is beneficial in plumping the skin, reducing the look of wrinkles and making skin look younger. A lot of Hyaluronic Acid serums will contain Sodium Hyaluronate as the key active ingredient.
Hyaluronic Acid can bind up to 1000 times its weight in water, which means it holds water molecules on the surface of your skin to keep it hydrated. The normal process of ageing can cause our skin to lose moisture. The key molecule in skin moisture is hyaluronic acid that has a unique capacity in retaining water. Sodium hyaluronate mixes easily with water and therefore when applied topically it attracts moisture in the skin cells which then reduces dryness and increases skin hydration.
A study on 40 healthy female subjects showing mild to moderate signs of ageing was carried out to discover the effect of hyaluronic acid on improving facial volume deficiencies. The effect of the treatment on skin surface and on face volumes was assessed both in the short-term (3 hours after product application) and in the long term (7, 14 and 30 days after continuous use). The subjects saw results right away, three hours after a single application and after 7,14 and 30 days of treatment the volume of their lips was increased by 8.5%, 11.3%, 12.8% and 14.2%. Skin sagging of the face had also significantly decreased, the volume of their cheekbones had increased, wrinkle volume was decreased and wrinkle depth was decreased. 
A study was conducted on individuals aged 18 to 75 years with mild to moderate facial rosacea. Their skin was measured on outcomes such as papules, pustules, erythema, edema, burning or stinging and dryness. They were measured on a five-point scale and were assessed at baseline, week 2, week 4 and week 8. When the results were in they found through visual grading assessments the sodium hyaluronate was shown to improve the global assessment by 47.5% from baseline to week 4. Reductions in papules, erythema, burning or stinging and dryness were 47, 51.7, 65 and 78.8 percent. At week 8 the global assessment was improved from baseline in 78.5% of subjects. Improvement was noted in measured clinical parameters with use of topical low molecular weight hyaluronic sodium. 
Hyaluronic acid has been studied for its wound healing abilities and has been proven to stimulate angiogenesis and exert fibrogenic action within inflamed and impaired healing tissues. HA is able to regulate inflammation levels by signalling the body to build more blood vessels in the damaged area . A case report on a man with a recurring ulcer found that by applying hyaluronic sodium salt gel twice daily helped the wound to completely heal over. 
Studies have also found that by applying it to skin wounds they are able to heal and recover faster and also less pain was documented than with placebo or no treatment at all. 
Hyaluronic acid that is applied directly to open wounds can reduce the chances of infection as it also has antibacterial properties. 
A systematic review on the effects of hyaluronic acid in dentistry found that it is effective in combating gum disease, speeding up healing after tooth surgery and eliminating ulcers when used topically in the mouth. 
As Hyaluronic Acid is found in the joints where it keeps the bones well lubricated, it has been studied for its effects on treating people with osteoarthritis and other joint conditions. Studies found that taking 80-200 mg of Hyaluronic acid per day for two months has shown to decrease knee pain in people with osteoarthritis. It can be taken orally or injected into the joints for pain relief. Some research shows that by combining the two ways, injecting hyaluronic acid and taking orally can extend the pain relieving benefits and increase the time between shots.   
Hyaluronic acid is generally safe to use as the body naturally produces it so very few allergic reactions have been recorded. It has not been studied on pregnant or breastfeeding women so caution for these women is advised if supplementing. Overall hyaluronic acid is a beneficial supplement which can help with a variety of conditions and is particularly beneficial for skin hydration, moisture and anti-aging.