What is the difference between hyaluronic acid, sodium hyaluronate, and hydrolyzed hyaluronic acid?

What is the difference between hyaluronic acid, sodium hyaluronate, and hydrolyzed hyaluronic acid on skincare product labels? Let's start with the most basic hyaluronic acid today. After peeling off the silk and analyzing layer by layer, you will finally understand what hyaluronic acid you bought at a high price is?

The following content is a synthesis of various knowledge circulating on the internet. If there are any similarities or errors, please self check and correct them. Finally, I will also share some shallow knowledge with everyone based on my years of experience in the industry, hoping to give more students more insight when purchasing products.

1. Basic knowledge of hyaluronic acid

1. Conceptual analysis

Hyaluronic acid, which already exists in the skin tissue, has super moisturizing power and is referred to as the "Key to the fountain of youth" on foreign websites.

Hyaluronic acid, also known as hyaluronic acid, HA， Natural moisturizing factor is an acidic viscous polysaccharide. It is almost a well-known natural water-soluble polymer that comes naturally with the human body. Lock in moisture, moisturize and form a film, and provide transdermal filling for wrinkle resistance. It is currently the most moisturizing substance found in nature, known as the ideal natural moisturizing factor. Biochemical drugs with high clinical value are widely used in various ophthalmic surgeries, such as lens implantation, corneal transplantation, and anti glaucoma surgery. It can also be used to treat arthritis and accelerate wound healing.

HA polymer exists between cells in the dermis and epidermis, serving as a filler for collagen fiber gaps and a component of the intercellular matrix in the epidermis. Its monomer is glucuronic acid plus acetyl glucosamine, with a molecular weight of around 388. The commonly used molecular weight ranges from 500000 to 2 million, as it hardly penetrates through the skin and has no safety issues when used. A mixture of HA with different sizes and molecular weights simulates natural HA in the skin, and its synergistic effect has higher efficacy.

The maturation and aging process of human skin also changes with the content and metabolism of hyaluronic acid. It can improve skin nutrition metabolism, make the skin soft, smooth, wrinkle free, increase elasticity, prevent aging, and is a good transdermal absorption promoter while moisturizing.

2. Classification

Small molecule hyaluronic acid: with a molecular weight of less than 500, as low as 50, it can penetrate directly into the dermis layer of the skin without injection, replenishing missing moisture and repairing damaged skin. At the same time, it promotes skin nutrient absorption, increases skin elasticity, and delays skin aging, truly playing a role in moisturizing and rejuvenating the skin, compensating for the deficiency of large and medium molecule hyaluronic acid. The texture is the softest and fluid, which is suitable for injection into the dermis or essence.

Large molecule hyaluronic acid: with a molecular weight greater than 1800, it cannot be directly absorbed by the skin, but has a film-forming effect. It can form a thin film on the surface of the skin to prevent the loss of trans epidermal moisture (TEWL), making the skin smooth and moist. It can also block the invasion of foreign bacteria, dust, and ultraviolet rays, protect the skin from damage, and make the skin soft and smooth. The texture is relatively hard and solid, usually used for injection molding and filling contours.

Medium molecular weight hyaluronic acid: The molecule is located in the 500-1000 channel and is similar to human skin cells. It can fill in the sunken areas of the skin and act on the deep tissues of the skin. The wrinkle removing effect can be maintained for a long time, restoring the skin's elasticity and fullness. The texture is slightly soft, suitable for filling soft tissues such as the nose, cheekbones, temples, and removing wrinkles and wrinkles from the eyes and forehead.

According to conventional understanding, the higher the molecular weight and the more added, the better the moisturizing and water absorbing performance. The requirements for the molecular weight and amount of hyaluronic acid in cosmetics often vary depending on the characteristics of the product.

The larger the molecular weight of large molecule hyaluronic acid, the stronger its water absorption and storage capacity, and the harder its texture. Therefore, it is usually used as an injection, and the injection volume and technique are also highly required to adjust the site according to the needs.

The larger the molecular weight of hyaluronic acid, the better the film-forming performance, but the poorer the permeability; On the contrary, the smaller the molecular weight, the softer the texture, and the stronger the permeability, which can enter the dermis layer and enhance its water storage capacity. However, its film-forming ability is poor and it cannot lock in the surface moisture of the skin.

Therefore, the first two are usually used for injection and transdermal filling. Small molecules are often used for smear absorption, and most of them are used as essence.

3. Extraction method

The production process and technology of hyaluronic acid determine the difference in quality, so products produced from the correct source must have therapeutic effects when used. Generally speaking, there are three methods for refining:

Animal tissue: The main raw materials are cockscomb and bovine vitreous humor. This method has an extremely low extraction rate of only about 1%, and the separation process is complex, resulting in the expensive price of hyaluronic acid, reaching $5000/kg, which limits its large-scale use in cosmetics.

Microbial fermentation: Fermentation broth using glucose as a carbon source. After 48 hours of fermentation in the culture medium, the mycelium and impurities are removed by filtration, and then high-purity products are obtained through simple operations such as alcohol precipitation. The advantage of using fermentation method to produce hyaluronic acid is that its molecular weight can be set according to the product design. The key to fermentation method lies in the selection of bacterial strains, such as streptococcus and lactobacilli.

Chemical synthesis: Using natural enzyme polymerization reaction and artificial synthesis method can greatly reduce the manufacturing cost of hyaluronic acid, but the structure is not pure.

The same hyaluronic acid product has a significant impact on its effectiveness due to differences in raw material sources and manufacturing techniques. The concentration of the product cannot be used as a reference for product selection, as purity, molecular weight, and 3D structure directly affect the water absorption effect of hyaluronic acid. Usually, the larger the molecular weight and the more complete the network structure, the better the water absorption effect. Skin care products and cosmetics are popular in the market, but many manufacturers make their own hyaluronic acid, which is cheap but not necessarily effective. Even the oral hyaluronic acid promoted by some people is broken down into small unit molecules of carbohydrates and amino acids after being absorbed by the gastrointestinal tract. It still needs to undergo self synthesis and other steps to be generated in the skin and connective tissue, and its effectiveness must be compromised.

Of course, not all ages and populations require a large amount of hyaluronic acid, especially those who are already very young, have compact skin texture, and relatively complete skin structure, and do not need to be constantly replenished and added.

For example, why do sandpipers have so many wrinkles? It is precisely because a substance called "hyaluronic acid" is excessively distributed throughout the skin of sandpipers that it causes so many wrinkles. And excessive hyaluronic acid is likely caused by overactivation of the gene called "hyaluronic acid synthase 2". Of course, as dogs grow older, sandpiper symptoms may eventually only manifest around the face, head, and neck.

Therefore, the more hyaluronic acid there is, the better. Appropriate hyaluronic acid can have anti-aging effects, lift and tighten, moisturize and nourish, while excessive hyaluronic acid can actually lead to the formation of "sand skin phenomenon".

2. Sodium hyaluronate

Sodium hyaluronate (SODIUM HYALURONATE) is a substance extracted from chicken crowns and can also be fermented by lactobacilli. It is a white or off white particle or powder, odorless, and has a nitrogen content of 2.8% -4.0% and a glucuronic acid content of 37.0% -51.0% when dried. It is widely used in the cosmetics industry and has a moisturizing effect. It is the product of neutralizing the carboxyl group of hyaluronic acid, in the form of sodium salt of hyaluronic acid, which improves water solubility, is easy to use, and is essentially no different from hyaluronic acid. Easy to use on oily or combination skin.

Hyaluronic acid is widely present in connective tissue, epithelial tissue, and nerve tissue. Commercial hyaluronic acid will be presented in its sodium salt form, called sodium hyaluronate.

Sodium hyaluronate, a large molecule, can form a breathable film on the surface of the skin, helping to lock in moisture and block the invasion of foreign bacteria, dust, and ultraviolet rays, protecting the skin from damage. Small molecule sodium hyaluronate can quickly penetrate into the dermis, slightly dilate capillaries, promote blood circulation, improve metabolism, promote skin cell nutrient absorption, and has the functions of wrinkle removal, skin elasticity enhancement, and delaying skin aging.

Most of the materials used for injection are sodium hyaluronate cross-linked polymers. It can be imagined that hyaluronic acid in its sodium salt form is more soluble in water, which facilitates penetration and absorption.

3. Hydrolyzed hyaluronic acid

Also known as low molecular weight sodium hyaluronate or small molecule sodium hyaluronate.

Angiogenesis is an essential process in normal tissue growth and wound repair, and low molecular weight hyaluronic acid can also counteract vascular loss caused by aging, radiation therapy, and other factors. Low molecular weight hyaluronic acid can protect granulation tissue from damage by oxygen free radicals and promote wound healing. Experimental results have shown that high molecular weight hyaluronic acid cannot penetrate through the epidermal layer into the dermis layer, while low molecular weight hyaluronic acid can penetrate into the dermis layer and eliminate oxygen freedom.

The low molecular weight method is to break down the high molecular weight hyaluronic acid through enzymes to obtain hyaluronic acid with a smaller molecular weight, in order to improve permeability. The permeability is faster and the molecular weight is smaller than that of hyaluronic acid. If high molecular weight sodium hyaluronate is used for moisturizing, filling, wrinkle removal and other effects on the skin, then low molecular weight sodium hyaluronate is more suitable for repairing skin mucosa and anti-inflammatory and anti-aging effects. Naturally, it will also appear in mouthwash, facial mask, skin facial mask spray, eye drops, vaginal protectors, etc.