Hyaluronic acid - real benefits and instructions for use according to a doctor and analyses by BeautyDecoders.
Hyaluronic acid is the most powerful humectant in cosmetics: one gram retains up to five liters of water, immediately plumping the skin and reducing dehydration lines. Applied topically, it moisturizes the epidermis, but has no proven anti-aging action, contrary to what the marketing suggests. To make the most of it, apply to damp skin and seal with a cream or SPF.
A humectant powerful
Hyaluronic acid is a humectant: it captures a very large quantity of water, making it the active ingredient of choice for hydration. Naturally present in our bodies (joints, muscles, skin), it plays a role in skin hydration and healing. With age, it diminishes in the dermis, under the effect of sunlight, free radicals and glycation, hence its use in aesthetic injections and cosmetics.
Its cosmetic benefits include exceptional moisturizing power (one gram attracts over five liters of water), an immediate plumping effect on fine lines, and a non-greasy, non-comedogenic texture. Another advantage is that it is suitable for both dry and oily skin. Along with collagen and elastin, it is one of the three essential components of the dermis, all produced by fibroblasts.
What he does really
In cream or serum form, hyaluronic acid does not penetrate to the dermis, but remains in the epidermis. Most products use molecules of different weights: the larger ones act on the surface, while the smaller ones penetrate a little deeper into the epidermis, without ever reaching the dermis.
What's more, hyaluronic acid is continually created and destroyed in the body: an enzyme, hyaluronidase, breaks it down in 24 to 48 hours. This is why the effect of a serum lasts 24 to 48 hours. Discovered in 1934 and widely studied, hyaluronidase has a solid track record in wound healing and aesthetic medicine, but little data on its anti-ageing effect when applied topically. A study of users on isotretinoin (suffering from severe dryness) showed that a hyaluronic acid cream significantly improved dryness and acne, but beyond that, evidence of a topical anti-aging effect is lacking.
The anti-aging myth topical application
Why has hyaluronic acid become one of marques's favorite active ingredients? For its real qualities (hydration, tolerance, immediate action), but also because the industry has long played on the confusion between the effect of injections and that of local application.
This confusion gives the impression of a topical anti-aging effect, to the detriment of actives that really have one, such as retinol, but whose use is more complex. Hyaluronic acid remains an excellent moisturizer - it is not an anti-aging active.
Can it cause reactions ?
Yes, but rarely in cosmetics on healthy skin. In hospitals, on wounds (with an altered skin barrier), some users developed reactions after ten days or so. In cosmetics, unusual redness may indicate poor tolerance to the very fine molecules of hyaluronic acid (potentially pro-inflammatory) or to another ingredient in the product. The right reflex: don't insist on using the product in question, try others before banishing hyaluronic acid, and stick to a simple routine to limit risks.
How to use it
It all depends on the format. A moisturizing cream often contains other humectants (glycerin), emollients and occlusives: no particular precautions are required, other than to apply it to slightly damp skin to maximize the effect. On the other hand, a serum containing only humectants, with no emollients or occlusives, can dry out the skin: the water attracted eventually evaporates. So always seal with a cream or sun cream containing emollients or occlusives. Exception: in very humid climates, hyaluronic acid draws water from the air, so an occlusive is optional.
Hyaluronic acid products choose ?
Here's a selection by format (lotion, serum, moisturizing sunscreen), with BeautyDecoded scores and user feedback. Remember: apply hyaluronic acid early in the routine, on damp skin, then seal with a cream or SPF.
Hada Labo Gokujyun Premium Lotion (lotion)
Best-selling lotion with five hyaluronic acids and glycerine, to be applied as a first layer after cleansing to replenish skin with moisture, on both dry and oily skin. Sensitive skin score -0.6 - slight caution, but very well tolerated. Texture a little thick, but effective moisturizer according to many faithful returns; very mature skins complete it with a rich cream to seal in hydration.
Nooance Sérum Multi-Actifs 5 Acides Hyaluroniques (serum)
Serum with five hyaluronic acids of different weights, with a light texture that plumps and smoothes, compatible with all other active ingredients. Sensitive skin score +0.25 - adapted, even for reactive skin. Feeling of hydration and smoother skin after a few weeks according to feedback; count five drops for the face, to be sealed with a cream or SPF to avoid evaporation.
The Ordinary Hyaluronic Acid 2% + B5 (accessible serum)
The benchmark hyaluronic acid serum at an affordable price, with provitamin B5 and ceramides for a simple, economical moisturizing base. Sensitive skin score +0.5 - adapted. Moisturizing and non-sticky for many, it must be applied to damp skin and then sealed: it's a pure humectant, and several reviews that found it drying used it on dry skin with no cream on top.
Skin1004 Hyalu-Cica Water-Fit Sun (moisturizing sunscreen)
Moisturizing sunscreen with hyaluronic acid and centella, perfect for sealing in moisture in the morning and illustrating the «always use an occlusive over hyaluronic acid» rule. Note from 4,91. Sensitive skin score -0.75 - slight caution. Fluid, invisible and non-greasy according to many feedbacks, an ideal make-up base; some users report that it can sting the eyes, like many sunscreens.
Find the right hydration for your skin profile.
The BeautyDecoded application lets you scan any cosmetic product to visualize its suitability for your skin type and needs, based on INCI analysis.
Your questions about hyaluronic acid
Is hyaluronic acid really anti-aging?
Should hyaluronic acid be applied to damp skin?
Hyaluronic acid for oily or dry skin?
Can hyaluronic acid and retinol be combined?
How long does a serum last?
Others associated guides
Information for educational purposes only. It does not replace a medical consultation and must be adapted to each individual. The compatibility scores generated by the application do not prejudge the individual tolerance of each skin type. A pure hyaluronic acid serum should be applied to damp skin, and always sealed with a cream or sunscreen. Hyaluronic acid injections are a medical procedure and require specialized consultation. In case of skin pathology or doubt, a dermatological opinion is recommended. A tolerance test should be carried out prior to first use.