Vitamin C

No trial has ever compared retinol with vitamin C for aging skin. Here is what each is actually shown to do, and where the evidence runs out.

Does vitamin C tighten saggy skin? No. The one trial to measure elasticity found a small dip, not a gain. Sagging is an elastin problem, not a diet one.

Surgery drops plasma vitamin C by 39% in the first week, and 21% of patients start deficient. What the evidence says about vitamin C wound healing.

Your body cannot finish a collagen fibre without vitamin C. What the evidence supports for skin, joints and tissue repair — and where it stops.