L-Ascorbic Acid
Ascorbic Acid
ALSO — VITAMIN C
The only vitamin C with a real evidence base. Also the least stable molecule we handle.
WHERE WE SIT IN THE PUBLISHED RANGE8% ——— 20%
15%
We compound toward the middle of the published range, not the top of it. Past the point where the dose–response curve flattens, the extra percent buys irritation and nothing else.
IDENTITY & RATINGSA
INCIAscorbic Acid
FAMILYAntioxidant / cofactor
MOL. WEIGHT176.12 g/mol
HOUSE CONC.15% w/w
pH WINDOW2.8 – 3.4
ACTS ATEPIDERMIS
DEPTH15 – 120 µm
ONSET8–12 WK
STABILITYOXIDISES — 90 D OPEN
TRIALS ON FILE3
IRRITATION INDEX3 / 10
STRATUM CORNEUM▸ EPIDERMISDERMIS
The shaded band is the depth this molecule is understood to reach. Anything below it is out of scope, whatever the label says.
01
Mechanism
EVIDENCE GRADE A
Essential cofactor for prolyl and lysyl hydroxylase — without it, collagen cannot cross-link. Separately quenches superoxide and regenerates oxidised vitamin E.
HOUSE NOTES
- Below pH 3.5 it penetrates. Above it, it does not. This is why the formula stings and why we will not raise the pH to make it pleasant.
- If it has turned amber, it has become dehydroascorbic acid. Bin it. That is what the batch date on the base is for.
02
Layering
CONFLICTS & PAIRINGS
DO NOT LAYER
- Retinaldehyde
- Copper Peptides
PAIRS WITH
- Vitamin E
- Ferulic Acid
- Zinc Oxide
03
Compounded into
1 FORMULAS