Also known as: HA, Sodium hyaluronate, Hyaluronan, Low molecular weight HA
Joint & ConnectiveGood evidence
A molecule that holds water in skin and joint fluid, best known topically but with a reasonable oral evidence base. Molecular weight determines whether an oral dose does anything at all.
Typical dose
120.0–240.0 mg per day
Daily, with or without food; allow 8-12 weeks
What it is
Hyaluronic acid is a glycosaminoglycan, a long chain of repeating sugar units, found throughout the body. Roughly half of the body's total sits in skin, with substantial amounts in the fluid that lubricates joints and in the eye.
Its defining property is water retention. A single gram can hold several litres of water, which is what makes it so useful in skin and in joint fluid, where it provides both cushioning and lubrication.
Molecular weight is the practical variable, and it is what separates a working oral product from an inert one. High molecular weight HA is too large to absorb intact and is broken down in the gut. Low molecular weight HA, generally under 500 kilodaltons, is absorbed to a meaningful degree. Most oral research uses the lower weight material, and a product that does not state its molecular weight tells you nothing useful.
How it works
In joint fluid, hyaluronic acid provides viscosity and cushioning, absorbing load and reducing friction between surfaces. Its concentration and molecular weight in joint fluid both decline with age.
In skin, it holds water in the dermis, contributing to hydration and to the mechanical properties that come with it.
How an oral dose produces effects is not fully settled. Absorbed fragments may be distributed to tissue and reused, but a more likely explanation is that fragments signal to cells to increase their own hyaluronic acid production. That would explain why oral doses far smaller than the amount present in tissue can still have measurable effects.
What the evidence shows
Skin hydration is the best-supported oral outcome. Several controlled trials have reported improvements in skin moisture and elasticity over 8 to 12 weeks, and reviews of this literature have been broadly favourable.
Joint comfort research is smaller but reasonably encouraging, with trials reporting improvements in comfort scores in adults with joint stiffness, generally over 8 weeks or more.
The literature carries the usual caveats: modest trial sizes, several industry-funded studies, and considerable variation in the molecular weight used. It is better evidenced than most people assume for an oral supplement, and less well evidenced than the topical and injectable applications it is famous for.
Dosing
Typical range is 120-240 mg daily. Skin hydration trials have most often used 120 to 200 mg, and joint trials a similar range.
Check molecular weight before buying. Low molecular weight material, under roughly 500 kilodaltons, is what the oral research used. A product advertising high molecular weight HA for oral use is selling you something that will largely be broken down before it does anything.
Take with or without food, consistently. Effects accrue over 8 to 12 weeks rather than quickly. It pairs logically with collagen peptides, since both target connective tissue from different angles and both depend on vitamin C for the underlying synthesis.
At a glance
Common forms
Low molecular weight HA, Sodium hyaluronate, High molecular weight HA (topical), Combined with collagen peptides
Half-life / duration
Tissue turnover is rapid; measurable effects accrue over 8-12 weeks
Timing
Daily, with or without food; allow 8-12 weeks
Competition status
Permitted — not on the WADA Prohibited List
Category
Joint & Connective
Safety and side effects
Oral hyaluronic acid is very well tolerated. Trials report few adverse effects, and those reported are mild and infrequent, mainly digestive upset.
It is a molecule the body produces in quantity, and oral doses are small relative to what is already present, which is consistent with the clean tolerability record.
Long-term data at supplemental doses is limited. Speak to your doctor before use if you take regular medication or are under medical care. Injectable applications are an entirely different proposition and belong under medical supervision.
Who should avoid it
Speak to your doctor before use if you take regular medication or are under medical care. Not established at supplemental doses in pregnancy or breastfeeding. Injectable forms should only be used under medical supervision and are not comparable to oral use.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
