Is hyaluronic acid the best moisturizer?

A common misconception is that hyaluronic acid is the best humectant and that it's essential to seek out and use moisturizing products that contain hyaluronic acid to keep skin well hydrated.

When you see all the marketing surrounding this ingredient, it's perfectly legitimate to think that it's the magic ingredient we need to have well-moisturized skin and erase wrinkles instantly. Of course, the cosmetics industry plays on the confusion between the effects of hyaluronic acid injections and the local application of hyaluronic acid in cosmetics. This confusion leads people to believe that local application of hyaluronic acid has anti-aging effects. Of course, this is totally false, but if it sells, science can wait. Having said that, products containing hyaluronic acid are not bad in themselves, unless you're allergic. There are simply other humectants that are much more interesting, and I'm going to show you just how.

As a reminder, humectants are molecules that attract water and moisturize your skin. I'm going to introduce you to 4 other humectants and, above all, I'm going to tell you about their molecular weight, which is important because in skin care, there's the 500 rule, i.e. above a weight of 500, molecules have enormous difficulty penetrating the skin barrier, although of course there are exceptions because other criteria come into play.

The different humectants

Visit glycerinIt's a natural favorite in cosmetics, and the first ingredient I look for when scanning the ingredients list of a moisturizing product. Its molecular weight is 92, well below 500, so remember that.
Urea is also an excellent humectant and NMF, a natural moisturizing factor. I should also point out that, in high concentrations, urea also has keratolytic properties. Its molecular weight is 60.
L'lactic acid is also a natural moisturizing factor and, as you know, an excellent exfoliating acid. Its molecular weight is 90.
The panthénol which is pro-vitamin B5, a humectant and emollient, and weighs 205.

Hyaluronic acid

And now hyaluronic acid, "the best ingredient for erasing wrinkles"! Its molecular weight varies from 20,000 to 2 million, and I do mean 20,000 to 2 million. And it's easy to see why hyaluronic acid, unlike glycerine, has trouble moisturizing the skin's deeper layers. Glycerin has a very low molecular weight, which enables it to hydrate the deep layers of the skin easily, whereas hyaluronic acid, with a molecular weight of 20,000 to 2,000,000, has trouble hydrating deep down.
To conclude with hyaluronic acid, it should be noted that the smallest molecules, from 20,000 to 50,000, can cause irritation, as hyaluronic acid particles of less than 50K daltons can be pro-inflammatory.
So now you understand why I prefer glycerine to hyaluronic acid, but I still have nothing against products containing hyaluronic acid, I just want to restore a bit of science. The idea is not to be swayed by marketing, and to do that you need to know how to decipher the list of ingredients, which will enable you to choose the products that suit you best.

Recommendations for hyaluronic-acid-free moisturizers:

For those with dry skin, Skin refiner de la neige is a lotion containing glycerine, liming oil (a vegetable oil) and green tea extracts. This lotion is really excellent for dry skin in winter.
And for moisturizing creams, Laroche Posay's tolériane sensitive, which contains niacinamide, ceramides and glycerine, is a cream that can be recommended for normal skin.