Twelve molecules. For each one: what it is, what it binds, how deep it gets, the concentration range the literature actually supports, where we sit inside that range, and what it costs you in irritation.
8 of the 12 score 0 or 1 on the irritation index. Those are the ones you can stack freely. The other 4 need a schedule.
Depth is the whole argument. A molecule that stops at the stratum corneum can change how skin looks this week and cannot change what it is made of. Only the third band decides lines.
Dead corneocytes in a lipid mortar. Everything optical happens here, and nothing structural does.
Live keratinocytes and melanocytes. Pigment is made here; turnover is set here.
Fibroblasts, collagen, elastin. The only layer where lines and laxity are actually decided.
| NO | ACTIVE | FAMILY | HOUSE | RANGE | IRRIT. | ONSET | GRADE |
|---|---|---|---|---|---|---|---|
| A-01 | Retinaldehyde | 0.1% | 0.03–0.2% | 4 | 8–12 WK | A | |
| A-02 | Palmitoyl Tripeptide-1 | 4% | 2–8% | 1 | 12–16 WK | B | |
| A-03 | Niacinamide | 5% | 2–10% | 1 | 4–8 WK | A | |
| A-04 | L-Ascorbic Acid | 15% | 8–20% | 3 | 8–12 WK | A | |
| A-05 | Azelaic Acid | 10% | 5–20% | 2 | 6–10 WK | A | |
| A-06 | Glycolic Acid | 8% | 4–12% | 5 | 2–4 WK | A | |
| A-07 | Ceramide NP | 2% | 0.5–3% | 0 | 1–2 WK | A | |
| A-08 | Hyaluronic Acid | 1% | 0.1–2% | 0 | IMMEDIATE | B | |
| A-09 | Bakuchiol | 1% | 0.5–2% | 1 | 12 WK | B | |
| A-10 | Tranexamic Acid | 3% | 2–5% | 1 | 8–12 WK | B | |
| A-11 | Panthenol | 3% | 1–5% | 0 | 1 WK | B | |
| A-12 | Zinc Oxide | 22% | 10–25% | 0 | IMMEDIATE | A |
Retinal
The strongest retinoid available without a prescription pad. Converts faster than retinol, irritates less than tretinoin.
Palmitoyl Tripeptide-1 + Palmitoyl Tetrapeptide-7
A forgery, essentially. We hand the fibroblast a fake breakdown signal and it rebuilds.
Niacinamide
The generalist. Barrier, tone, oil and pore visibility all move a little. Nothing moves a lot.
Ascorbic Acid
The only vitamin C with a real evidence base. Also the least stable molecule we handle.
Azelaic Acid
Treats redness, post-inflammatory pigment and breakouts at once. Almost nothing else does all three.
Glycolic Acid
Removes the layer that is scattering light. Immediate optical payoff, real irritation ceiling.
Ceramide NP
Not a moisturiser. A replacement part. Ratio matters more than concentration.
Sodium Hyaluronate (multi-weight)
Does nothing structural. Does a great deal optically, within the hour.
Bakuchiol
For skin that cannot tolerate A-01, or for pregnancy. Weaker. Honestly weaker.
Tranexamic Acid
The pigment active that works on the vascular component — the one that survives sun exposure.
Panthenol
The quiet one. Its whole job is making the other actives survivable.
Zinc Oxide (non-nano)
The single highest-return active in the formulary. Every other product here is repairing what this one prevents.