The evidence does not point to drinking more water being a meaningful remedy for dry skin or wrinkles. For skin hydration and wrinkle reduction, collagen peptides have better support, but the quality of that evidence is moderate, in part due to commercial involvement in the studies. Chronically drinking too little is linked to accelerated ageing in a broader sense, but that relationship has not yet been proven to be causal either.
Drinking more water has a limited but measurable effect on the moisture content of the upper skin layer. A systematic review of six studies found a slight increase in skin hydration, particularly in people who previously drank little. The biological mechanism behind this effect is still unknown, and whether it also works in older adults is unclear. The evidence is sparse and of limited quality.
For wrinkles, there is no evidence whatsoever that drinking more water helps. The systematic review even explicitly calls for more research into this relationship, which indicates how little we currently know about it. Anyone who drinks more water in the hope of reducing wrinkles has no scientific basis for doing so.
Chronic underhydration is a different matter from simply drinking an extra glass of water. A large 2024 review study links persistently insufficient fluid intake, measured via blood values and urine, to an increased risk of accelerated ageing and chronic disease. This is for now a statistical association, not a proven causal relationship. Intervention studies to confirm this are still ongoing. The lesson is: structurally drinking too little may, in the long run, be harmful in ways that go beyond the skin alone.
When it comes to skin hydration and wrinkles specifically, collagen peptides currently have the strongest support among the remedies studied. Two placebo-controlled, double-blind RCTs showed that 1000 mg of collagen peptides daily for 12 weeks significantly improved skin hydration, elasticity and wrinkle depth compared with placebo. A third study also showed improvement of the collagen network in the deeper layers of the skin, after as little as four weeks. No side effects were reported. One caveat: several of these studies were (co-)funded by the manufacturer of the product, which may influence the results. A combination drink containing collagen peptides plus vitamin C, zinc and biotin also showed positive effects, but it is unknown which ingredient makes the difference.
Co-enzyme Q10, an antioxidant, showed fewer wrinkles and improved skin suppleness in one small RCT (33 participants) at doses of 50 to 150 mg per day over 12 weeks. However, it had no effect on skin hydration. This study is too small to draw firm conclusions from; confirmation by larger studies is still lacking.
Based on one systematic review (6 studies, PMID 29392767 and 30609670), one large epidemiological review study (PMID 38409366), three placebo-controlled RCTs on collagen peptides (PMID 29949889, 31627309, 26362110) and one small RCT on co-enzyme Q10 (PMID 27548886). Two collagen studies disclose (co-)funding by the manufacturer.