What you need to know about hyaluronic acid.

A combination of uronic acid and an aminoglycan, hyaluronic acid was first discovered in the vitreous humour of a bovine eye in 1934 by Karl MEYER and John PALMER from the Department of Ophthalmology at Columbia University in New York. It was subsequently extracted from the cartilage of a bovine snout and the comb of a rooster. Today, the hyaluronic acid used in cosmetic products is typically obtained through biotechnological synthesis from bacteria.

This biomolecule is a complex sugar that is extremely hydrophilic. Naturally present in the human body, it can be found around the joints, in the muscles, in the eye... However, the skin, and more specifically the dermis, remains the primary reservoir of this molecule in the human body.

Hyaluronic acid's function is to ensure skin hydration. Within the dermis, it helps to form its connective tissue and serves as a support to collagen and elastin fibres. Thus, it plays a fundamental role in the density and the tonicity of the skin. However, over the years, the body's production of hyaluronic acid tends to decrease (a drop of about 6% per decade), which leads to the appearance of the first wrinkles and fine lines on the surface of the epidermis. Therefore, it is beneficial to supply it to the epidermis through dermocosmetic skin care applications.

Hyaluronic acid is a highly hydrophilic complex sugar. In other words, it acts like a sponge: it has a strong affinity for water and retains it. When applied to the skin, depending on its size, it can fulfil several functions:

• High molecular weight hyaluronic acid :

  It remains on the surface of the epidermis and creates a protective film that prevents water from evaporating. It also hydrates the superficial layers of the skin and provides a tightening effect.

• Low molecular weight hyaluronic acid :

  Being a smaller molecule, it penetrates deeper into the epidermis, reaching the base of the corneal structure, to revitalise the skin. It strengthens and stimulates the production of hyaluronic acid naturally produced by the body.

  
  

This molecule is present in numerous facial care products (serum, cream, toner, cleansing gel) as well as body care items (milk, hand balm, nail and cuticle serum). Hyaluronic acid is also a component in hair care products such as serums, shampoos, masks and conditioners. It prevents split ends, helps to tame unruly hair and restores shine to dull hair.

Typology has developed several products containing this potent hydrating agent capable of retaining up to a thousand times its own weight in water:

• Combined with aloe vera for comprehensive moisturising action, the hydrating toner helps to balance the skin's pH following the cleansing/makeup removal stages.

• The plumping serum is composed of 94% natural origin ingredients and makes the skin more supple after just a few weeks of use.

• The nourishing face cream is enriched with lipid-replenishing and moisturising active ingredients and is composed of 98% natural origin ingredients. It restores suppleness to the skin and reduces feelings of tightness.

• The moisturising cleansing milk contains 0.5% ofhyaluronic acid combined with chamomile extract. This skincare product removes impurities without drying out the skin. It contains a base of gentle, biodegradable surfactants of natural origin that create a delicate foam to cleanse the skin while respecting its balance. It is applied to damp skin in the morning and/or evening, directly with the fingers. The milk emulsifies on contact with water into a fine foam, facilitating the rinsing stage.
  

• Enriched with hyaluronic acid and organic coconut oil, the face moisturising cream with 9 ingredients is a minimalist formula that hydrates and nourishes the epidermis. Its light and non-greasy texture is suitable for dry, normal and combination skin, even sensitive ones.

• The face sunscreen with an SPF30 is enriched with hyaluronic acid to prevent your skin from dehydrating while protecting it from the harmful effects of UVA/B rays.

• The hand & nail serum helps to strengthen your nails and smooth out roughness, in combination with plant keratin.

• The hand balm with 10 ingredients is suitable for all skin types, including sensitive skin. This minimalist formula care product is enriched with hyaluronic acid to combat dryness and potential irritations.

• The restorative lip mask forms a protective film on the lips, thereby limiting the evaporation of water and helping to rehydrate and repair damaged lips. Enriched with mango butter, this mask melts onto the lips and leaves a feeling of softness. Also included in its formula are ceramides, which have a lipid-replenishing action, and hyaluronic acid which is highly moisturising.

When applied topically, hyaluronic acid is a molecule generally well tolerated by all skin types and does not appear to have a sensitising potential. It does not present any undesirable side effects in cosmetics.

When injected, it can nonetheless pose some risks. According to the ANSM, 0.1 to 1% of individuals have experienced side effects following a hyaluronic acid injection, such as haematomas, minor bleeding, or oedemas. However, these inconveniences remain rare and fade within a few days.

• DINI G. & al. Hyaluronic acid in cutaneous intrinsic aging. International Journal of Dermatology (1994).

• MICHELOTTI A. & al. Anti-aging and filling efficacy of six types hyaluronic acid based dermo-cosmetic treatment: double blind, randomized clinical trial of efficacy and safety. Journal of Cosmetic Dermatology (2014).