Does L-carnitine help to firm the skin?

The L-carnitine is a molecule naturally present in the body, primarily known for its role in energy metabolism by facilitating the transport of fatty acids into mitochondria. However, in recent years, L-carnitine has also attracted growing interest in the cosmetic field, for its ability to care for oily skin but also for its potential effects on skin firmness and quality. Several biological pathways can explain this action, and some clinical data support these hypotheses.

An intriguing first mechanism of L-carnitine relates to its antioxidant activity. L-carnitine can scavenge reactive oxygen species generated particularly during UV exposure. These free radicals directly contribute to the breakdown of collagen and elastin, two proteins that ensure skin suppleness and elasticity. By limiting this oxidative stress, L-carnitine helps to preserve the integrity of the extracellular matrix, thus reducing skin laxity and loss of firmness.

Meanwhile, L-carnitine exerts a inhibitory effect on the matrix metalloproteinases MMP-1 and MMP-2, demonstrated in in vitro. These enzymes, notably activated by UV radiation and oxidative stress, are responsible for the degradation of collagen and other components of the dermal matrix. Their inhibition helps slow the breakdown of connective tissue and promotes the maintenance of smoother, firmer skin. Thus, through both an antioxidant action and a direct effect on MMPs, L-carnitine appears to protect the skin’s structural integrity.

These hypotheses were tested clinically. A pilot study was carried out on 50 women divided into two groups: one receiving a cream containing 1% L-carnitine, the other a placebo. The volunteers applied the formulation twice daily to the entire face for 12 weeks. Efficacy was clinically assessed by visiometry. The researchers observed that L-carnitine resulted in a significant decrease in two skin roughness parameters (R2 and R3), indicating a reduction in wrinkles compared with placebo. No adverse effects were reported, confirming the good tolerability of the active ingredient. These data therefore suggest a genuine benefit of L-carnitine in improving skin firmness and texture after three months of regular use.

While this study sheds light on a promising effect of L-carnitine on skin firmness, it should be emphasised that, at present, it is based on a single clinical trial. L-carnitine remains a relatively under-researched active ingredient, and although its potential is genuine, it is advisable to remain cautious and await confirmation of these results through further, larger-scale research.

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