What actually works after forty, and what simply costs more.
Retinol is the single most-studied anti-ageing ingredient in dermatology. The $180 serum and the $20 one often contain the same active at the same strength. We looked at four tiers side by side.
- The questionDoes retinol concentration scale with price?
- The findingNot reliably. Encapsulation, delivery, and vehicle matter as much as cost.
- The caveatFormulation elegance, texture and tolerability are real reasons some pay more.
- StatusResearched · Compared