The following supplements improved one or more markers of skin health:

Collagen peptides reduced wrinkles (large effect size), improved skin hydration (moderate effect size), and slightly reduced pigment spots (small effect size).
Carotenoids reduced skin redness (moderate effect size).
Polyphenols reduced wrinkles (small effect size), improved hydration (moderate effect size), and improved barrier integrity (moderate effect size).
Prebiotics and probiotics improved skin hydration (moderate effect size).
Lipids and fatty acids — such as ceramides — reduced wrinkles, improved hydration, and increased skin elasticity (all with a moderate effect size).

The supplements were taken for 2 weeks to 6 months. The control groups received a placebo, an active comparator (such as another nutrient), or no intervention.

Supplements for skin health: a closer look at the evidence Original paper