It is natural for the body to change over time and with hormonal fluctuations. As we age, the skin becomes thinner, drier and tends to lose its suppleness. Skin cells renew less and less effectively, leading to an accumulation of dead cells. Additionally, the activity and number of fibroblasts decrease, resulting in a reduction in the synthesis of collagen and elastin, which are responsible for the firmness and elasticity of the skin. It is also worth noting that the production of squalene and other sebum constituents by the sebaceous glands decreases over time. The hydrolipidic film then becomes more fragile, which accentuates skin dryness.
To prevent skin ageing and its signs, an external supply of squalene can be beneficial. However, this compound is rarely used in cosmetic formulation, due to its sensitivity to oxidation. Indeed, the oxygen in the air or heat can transform it into squalene peroxide, a comedogenic compound. To avoid this, the squalane, obtained by hydrogenating squalene and more stable than the latter, is preferentially used in cosmetics. This lipid acts like the squalene in sebum to hydrate the skin and strengthen the skin barrier and the hydrolipidic film, which prevents dehydration. Squalane thus helps to protect the skin against external aggressions and to preserve its elasticity and suppleness. A functional skin barrier is indeed one of the keys to maintaining smooth skin for as long as possible and preventing wrinkles.
Little research has been conducted on the ability of squalane to prevent ageing. However, one study can be mentioned, which focused on the effect of squalane combined with bakuchiol on skin hydration and elasticity. For 28 days, 47 women applied a serum daily containing these active ingredients. A decrease attributed to squalane of approximately 3.76 g/h/m2 in water loss was measured, along with an average increase of 11.9% in skin elasticity. However, it is difficult to determine whether squalane truly contributed to improving skin suppleness or if the bakuchiol was solely responsible. Indeed, apart from its humectant power, squalane does not seem to be able to target skin ageing specifically.
The key takeaway : The moisturising properties of squalane are beneficial in slowing down skin ageing. However, for a comprehensive preventive effect, it is advisable to combine it with firming and antioxidant agents.