What to take for skin

Graded by the strength of the evidence — strongest first. Nothing here is sold to you.

Collagengrade Csmall improvements in skin elasticity/hydration in industry-funded trials
Collagengrade Csmall improvements in skin elasticity/hydration in some RCTs; industry-funded bias common
Vitamin Cgrade Ctopical better-supported than oral; oral may support collagen synthesis
Zincgrade CAcquired zinc deficiency is deeply involved in the development of skin diseases including acquired acrodermatitis enteropathica, necrolytic migratory erythema, alopecia, and delayed wound healing, and mutations or dysregulation in zinc transporters are associated with skin manifestations.