Beauty From Within: What the Evidence Actually Supports

30 Jun 2026

Supplements are the least regulated corner of the beauty aisle, and the gap between marketing and evidence is wide. A few ingredients hold up; most do not.

Reasonable evidence

• Omega-3 fatty acids — supportive for barrier function and inflammatory skin conditions.
• Hydrolysed collagen peptides — modest, measurable effects on skin elasticity in several trials.
• Vitamin D, where you are actually deficient — worth a blood test rather than a guess.

Thin evidence

Biotin does very little unless you have a genuine deficiency, which is rare. Sleep, sun protection, and not smoking still outperform every powder on the shelf.