Ingredients - The index
Vitamin C is worth using and impossible to store
The mechanism is well documented. The problem is that the molecule is unstable, and most of the argument you read online is about formulation, not biology.
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Ingredients
The running reference for the actives that do most of the work.
Edited by BeautyTalks Editors
The index
What to layer, what to leave a night between
| Active | What it actually does | Use it | Pairs with | Not the same night |
|---|---|---|---|---|
| Glycolic acid | An alpha hydroxy acid that loosens the bonds between surface corneocytes. | PM, 1-2x a week | - | - |
| Niacinamide | Supports barrier lipid synthesis and moderates sebum. One of the few actives that plays well with everything. | AM or PM, daily | - | - |
| Retinal | A retinoid one conversion step from retinoic acid, so it works faster than retinol at similar tolerability. | PM, 2x a week to start | Niacinamide | Glycolic acid |
| Retinol | The most studied over-the-counter retinoid; two conversion steps from retinoic acid. | - | - | Salicylic acid |
| Salicylic acid | A beta hydroxy acid that is oil-soluble, so it works inside the pore rather than only on the surface. | - | - | - |
| Vitamin C | An antioxidant that also inhibits pigment transfer; unstable in water at high pH. | - | - | - |