Oral hyaluronic acid: how is it supposed to work?

In a serum, hyaluronic acid is fairly easy to picture.

In a capsule, much less so.

You swallow it. It reaches the stomach. And yet, a few weeks later, some studies measure changes in the skin.

So what happens between the two?

No, it does not go directly to “fill” the skin

Hyaluronic acid, or hyaluronan, is a glycosaminoglycan naturally present in many tissues, including skin.

But after ingestion, a large molecule is not simply sent intact to the dermis.

Mechanistic work suggests that some HA is broken down in the intestine, including through the action of the gut microbiota, into fragments and metabolites that can then be absorbed or participate in other biological pathways.

The most detailed work on this journey is still largely based on animal research.

It makes a mechanism plausible. On its own, it does not prove a skin benefit in humans.

Molecular weight is part of the material’s identity

Hyaluronic acid is a chain whose size can vary enormously.

Two products that both say “hyaluronic acid” can therefore use very different molecular-weight distributions.

This size influences viscosity, degradation and biological interactions, among other things.

It is not a detail to leave to chemists. It is one of the reasons why a study on one material cannot automatically be transferred to another.

Human trials have existed for several years

In 2015, a controlled trial in 61 people with dry skin compared 120 mg per day of 800 kDa HA, 300 kDa HA or placebo for six weeks.

Both HA groups showed favourable results for skin moisture during the ingestion period.

In 2017, another trial in 60 adults studied 120 mg per day of 2 kDa or 300 kDa HA for twelve weeks and reported favourable differences in several wrinkle parameters.

Several authors were employees of the manufacturer involved. That is not a reason to discard the study. It is a reason to keep the context visible.

In 2025, the meta-analysis becomes interesting

A meta-analysis brought together seven randomised controlled trials of oral HA.

It found statistically significant improvements in hydration, elasticity and wrinkle depth.

However, not every parameter improved, and the authors highlighted the small number of studies and their heterogeneity.

Another review published the same year, focused specifically on photoageing, reached a less favourable interpretation for some outcomes.

That is not necessarily contradictory: the two papers did not select exactly the same questions or outcomes.

At Eclo: why ExceptionHYAL® Star?

In our Hyaluronic Acid 200 mg formula, we use 224.8 mg of ExceptionHYAL® Star to provide 200 mg of hyaluronic acid per daily dose, with 80 mg of Quali®-C vitamin C.

ExceptionHYAL® Star is described by its manufacturer as a “full-spectrum” hyaluronan with several molecular weights.

A randomised, double-blind, placebo-controlled trial published in 2021 evaluated 200 mg per day of full-spectrum hyaluronan ExceptionHYAL® Star in 60 women for 28 days.

This publication interests us because it directly concerns the raw material we selected.

It is still not a clinical study of the finished Eclo product.

What about Ressource™?

Ressource™ also provides 200 mg of hyaluronic acid via ExceptionHYAL® Star, within a broader formula that includes 30 mg of Céramosides™ and magnesium bisglycinate, among other ingredients.

The choice between the two is therefore not “more or less HA”.

It is more a question of a targeted formula versus a multi-active formula built around hydration and the skin barrier.

Five questions to ask about an HA supplement

Oral hyaluronic acid becomes much more interesting when we stop imagining it as a serum that has learned how to travel.