Does hyaluronic acid applied to your skin actually help against dryness and wrinkles?
Hyaluronic acid on your skin genuinely helps against dryness. Injections work most powerfully against wrinkles. A pill or powder adds little if you are already taking collagen.
Hyaluronic acid in creams and serums demonstrably works: several clinical studies show improved skin hydration and less visible wrinkles1,2. One caveat: one literature review had an author employed by L'Oréal, the manufacturer of the product being studied. That is a serious conflict of interest. The remaining studies do support the effect on hydration, but the exact size of that effect varies from study to study.
Injections have the strongest evidence base. In a study with 146 participants, superficial wrinkles on the face, neck and décolleté decreased significantly after a series of micro-filler injections, visible at day 75 and day 120 compared with cream alone3. Side effects were mild and resolved within 48 hours. Note: this study was funded by the manufacturer of the product (FILLMED). The classic hyaluronic acid filler is the most widely used dermal filler worldwide. It attracts water, improves wrinkles and volume loss, and is reversible with an enzyme injection, which makes it relatively safe4.
For oral supplements the picture is more nuanced. An analysis of seven controlled studies shows significant improvements in hydration, elasticity and wrinkle depth5. However, effects on firmness, wrinkle volume and transepidermal water loss were not significant. The researchers themselves caution that participant numbers are small and that the studies vary considerably. Larger studies are needed.
Combining collagen with vitamin C? Then oral hyaluronic acid adds nothing to it. In a rigorous double-blind study with 87 women over 16 weeks, collagen combined with vitamin C noticeably improved the skin, but adding oral hyaluronic acid provided no additional benefit for hydration, elasticity or any other measured outcome6.
Finally: a review article on hyaluronic acid as a 'skin booster' has been retracted by the publisher and does not count as a reliable source7. This type of article occasionally appears in advertising materials, so it is worth knowing that.
Based on one analysis of seven controlled studies (oral hyaluronic acid), three clinical controlled studies on injectable and topical applications, one literature review with possible commercial bias (author employed by L'Oréal), one small split-face study (27 participants, PMID 32248707) and one retracted review (excluded). One study was funded by manufacturer FILLMED.