Actives glossary
Retinol
The retinoid most cosmetic products use, two conversion steps away from the form skin actually responds to.
- INCI name
- Retinol
- Also called
- vitamin A alcohol
- Family
- Retinoid
- Range seen on labels
- 0.1% to 1%, when a brand states a figure at all
- Sits well with
- niacinamide, ceramides
- Needs care with
- glycolic-acid, salicylic-acid, tretinoin
Retinol is the cosmetic workhorse of the retinoid family. Skin converts it in two steps, first to retinaldehyde and then to retinoic acid, and only that final form binds the receptors that change how skin behaves. Each conversion step loses material, which is why a retinol percentage and a prescription retinoid percentage are not comparable numbers even when they look alike.
What the percentage does and does not tell you
A stated 0.5% tells you how much retinol went into the batch. It does not tell you how much survives in the bottle at month six, because retinol oxidises on contact with air and light. Two products at the same percentage can differ by a lot depending on whether the retinol is encapsulated, what the vehicle is, and whether the pack lets air in.
That is why an opaque airless pump matters more here than in most categories, and why a clear dropper bottle is a real mark against a retinol product regardless of its number.
Encapsulation
Encapsulated retinol is wrapped in a carrier that releases it slowly. Brands use it for two different reasons: to reduce the irritation that comes with a fast dose, and to protect the molecule from oxidising. Both are real. Neither is measurable from the outside, and no brand in our retinol ranking publishes a release profile, so encapsulation is scored as a stated formulation choice rather than as a verified benefit.
What it does not do
Retinol is a cosmetic ingredient. It changes the appearance of lines, tone and texture over months of consistent use. Claims that go further belong to prescription products and to clinicians, not to a serum you buy without one.