Hyaluronic acid for the skin: what it is, what it's for, and how to use it correctly

Reviewed by Souad Charifi Hadj, registered pharmacist no. 2676.

Hyaluronic acid for skin is probably the most famous moisturizing ingredient in cosmetics today… and also one of the most misunderstood. It’s credited with miracles, confused with the injections used by aesthetic doctors, and almost no one knows that the key to its effectiveness (or lack thereof) lies in a tiny detail: its molecular weight. In this article, we’ll tell you, without hype and with science in hand, what it is, what it’s really for, and how to use it in your natural skincare routine to make your skin look plump even in the middle of summer.

Quick answer: Hyaluronic acid is a molecule that your skin produces naturally, and its main function is to retain water. Applied topically, it attracts and locks moisture into the superficial layers of the skin, resulting in more hydrated, elastic, luminous skin with visibly softened fine lines. It doesn't "fill" wrinkles permanently like an injectable, but it significantly improves the appearance of dehydrated skin without irritation.

What is hyaluronic acid?

Hyaluronic acid (sometimes abbreviated as HA) is a glycosaminoglycan: a long, sugar-like molecule that is a natural part of the matrix of our skin, eyes, and joints. Its superpower is its ability to retain water: it can bind up to nearly a thousand times its weight in water, making it largely responsible for young skin looking plump, resilient, and flexible.

The problem is that its quantity decreases with age and due to external factors like sun exposure. According to a review published in Dermato-Endocrinology, hyaluronic acid is "the key molecule involved in skin hydration," and its decrease is directly related to loss of firmness and the appearance of wrinkles. That's why replenishing it from the outside makes so much sense within an anti-aging and facial hydration routine.

What is hyaluronic acid for skin?

Hyaluronic acid for skin is not just another moisturizer. Its benefits, backed by clinical studies, can be summarized as follows:

• Deep and immediate hydration: it draws water to the epidermis and helps maintain it, leaving the skin more flexible and comfortable from the first application.
• "Plumping" effect on fine lines: by swelling with water, the superficial layers of the skin gain volume, and dehydration wrinkles appear softened.
• Increased apparent elasticity and firmness: well-hydrated skin bounces back better and looks smoother.
• Luminosity: plump skin reflects light better, creating that famous glow effect.
• Support for the skin barrier: it helps the skin lose less water, which is especially useful after sun exposure, air conditioning, or sea water.

A classic study by Pavicic and colleagues, published in the Journal of Drugs in Dermatology, showed that topical application of hyaluronic acid for 60 days significantly improved skin hydration and elasticity, and that low molecular weight versions also reduced the depth of periorbital wrinkles. And here we get to the detail that changes everything.

High or low molecular weight: why it matters (a lot)

Not all hyaluronic acids are the same. The difference lies in the size of the molecule, or molecular weight, and it determines how far it penetrates and what it does:

• High molecular weight: large molecule that stays on the surface. It forms a film that hydrates, instantly smooths, and protects against water loss. Ideal for an immediate "good face" effect.
• Low molecular weight: smaller molecule that penetrates deeper into the epidermis. This is associated with greater improvement in fine lines and more lasting hydration.

The best formulated serums combine several molecular weights to hydrate at different levels simultaneously. When choosing a facial serum, look for mentions of "low and high molecular weight hyaluronic acid" or "multimolecular hyaluronic": this indicates a well-thought-out formula.

Hyaluronic acid and natural cosmetics: where is it sourced from?

Many people assume that hyaluronic acid is a "laboratory" ingredient and not very compatible with natural cosmetics. The reality is more beautiful: today, the vast majority of cosmetic hyaluronic acid is obtained through bio-fermentation, that is, through bacterial fermentation of plant sources such as wheat or corn. It is a vegan process (it used to be extracted from rooster combs, which is now obsolete), sustainable, and very gentle on the skin.

That's why hyaluronic acid fits perfectly into a conscious beauty routine: it's identical to what your skin recognizes, it's produced cleanly, and it combines wonderfully with other natural active ingredients like aloe, vegetable oils, or antioxidant botanical extracts.

How to use hyaluronic acid in your routine step by step

Using it correctly is as important as choosing it well. Here is the recommended order:

1. Cleanse your face with a gentle cleanser.
2. Apply hyaluronic acid to slightly damp skin, not completely dry. This trick is key: hyaluronic acid needs water to "grab onto"; if your skin and the environment are very dry, it can draw moisture from deeper layers and be counterproductive.
3. Seal with a cream or oil over it. This step is non-negotiable: the cream traps the water that hyaluronic acid has attracted. Without sealing, the effect evaporates.
4. During the day, always finish with sun protection.

In summer, when the sun, salt, pool chlorine, and air conditioning mercilessly dehydrate the skin, hyaluronic acid becomes your best ally to maintain that plump skin feeling. A simple gesture after showering makes all the difference.

Common mistakes to avoid

• Applying it to dry skin in a dry environment and not sealing afterward: this is the perfect recipe for it to draw from your own hydration.
• Expecting it to erase deep wrinkles: cosmetics hydrate and smooth, they do not replace medical treatment or injectables.
• Using only hyaluronic acid as your sole hydration: it works best accompanied by lipids (creams or oils) that strengthen the barrier.

Is it suitable for all skin types?

Yes, and that's one of its great virtues. Being a molecule that the skin recognizes as its own, hyaluronic acid is very well tolerated, even by sensitive, reactive, or acne-prone skin. It doesn't add oil, so combination and oily skin types appreciate it as a source of light hydration. And dry or mature skin types find it essential for regaining comfort and that rested look we seek in any anti-aging and anti-wrinkle routine. As always, if you have a specific dermatological condition, it is ideal to consult with a professional.

In summary: an essential that deserves its reputation

Hyaluronic acid has earned its place on the altar of star ingredients because it delivers on its promises: it hydrates, smooths, and provides luminosity safely and for all skin types. The key is to choose formulas with various molecular weights, apply it to damp skin, and seal it well. If you want to incorporate it into your natural skincare routine, at Biovardi you'll find a selection of serums and facial hydration products with clean and effective active ingredients, and you can always request free pharmaceutical advice to find the one that best suits you.

Frequently asked questions about hyaluronic acid

Does hyaluronic acid in cream or serum have the same effect as injections?

No. Cosmetics act on the surface of the skin, hydrating it and smoothing dehydration lines. Injectable fillers (aesthetic dermatology) deposit hyaluronic acid in deeper layers to provide temporary volume. These are different uses and results.

Can it be used every day?

Yes. It is suitable for daily use, morning and night, and combines well with other active ingredients such as vitamin C, niacinamide, or retinal/bakuchiol. Remember to apply it to damp skin and seal with a cream.

Does hyaluronic acid dry out the skin?

It can give that sensation if applied to very dry skin, in a dry environment, and without sealing afterward, because it draws water from the deeper layers. Applied correctly—to damp skin and with a cream on top—it hydrates, it does not dry out.

Is it vegan and natural?

Current cosmetic hyaluronic acid is primarily obtained through bio-fermentation from plant sources, which makes it vegan and sustainable, and perfectly compatible with natural cosmetics.

At what age should you start using it?

There is no "official" age. As a well-tolerated moisturizer, it can be used from a young age as a source of light hydration, and it becomes especially relevant from age 25-30, when natural production begins to decline.

References

• Papakonstantinou E, Roth M, Karakiulakis G. Hyaluronic acid: A key molecule in skin aging. Dermato-Endocrinology. 2012;4(3):253-258. View study
• Pavicic T, Gauglitz GG, Lersch P, et al. Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. J Drugs Dermatol. 2011;10(9):990-1000. View study
• Guerra Tapia A, Gómez de la Fuente E. El ácido hialurónico y sus aplicaciones en dermatología. Actas Dermo-Sifiliográficas. View article