What pH does Vitamin C work at?

Vitamin C is most effective at a pH of <3.5 (L-ascorbic acid form).

What pairs well with Vitamin C?

Vitamin C pairs well with: ferulic acid (improves stability and efficacy), tocopherol, squalane.

Is Vitamin C safe during pregnancy?

Vitamin C is generally considered safe during pregnancy. Always confirm with your obstetrician.

What should I not mix with Vitamin C?

Use with caution alongside: high-pH formulas (deactivates); copper peptides in same step (oxidation).

The guides · Antioxidants

Vitamin C

Q: What does Vitamin C do in skincare?

L-ascorbic acid — antioxidant that supports the look of brighter, more even tone. Neutralizes free radicals before UV damage compounds. Requires pH <3.5 for optimal skin penetration.

Q: What pairs well with Vitamin C?

Vitamin C pairs well with: ferulic acid (improves stability and efficacy), tocopherol, squalane.

Q: Is Vitamin C safe during pregnancy?

Vitamin C is generally considered safe during pregnancy. Always confirm with your obstetrician.

Q: What should I look for on the label when buying a Vitamin C product?

Look for "l-ascorbic acid" or "ascorbic acid" — not just "vitamin C". Dark glass or sealed pump packaging is non-negotiable. A clear or oxidised-looking serum means degraded product.

Q: What should I not mix with Vitamin C?

Use with caution alongside: high-pH formulas (deactivates); copper peptides in same step (oxidation).

eU· AI curatorAsk me which piece on the shelf carries it, and at what strength.

L-ascorbic acid — antioxidant that supports the look of brighter, more even tone. Neutralizes free radicals before UV damage compounds. Requires pH <3.5 for optimal skin penetration.

I · 2 min read

What it does

L-ascorbic acid — antioxidant that supports the look of brighter, more even tone. Neutralizes free radicals before UV damage compounds. Requires pH <3.5 for optimal skin penetration.

The facts

Effective pH: <3.5 (L-ascorbic acid form)
Category: Antioxidants
Also known as: L-ascorbic Acid, Ascorbic Acid, Vitamin C Serum
Pregnancy: Generally considered fine; ask your doctor

III

Pairs with · fights with

Pairs well with

Ferulic Acidimproves stability and efficacy
Tocopherol
Squalane

Conflicts

High-pH formulasdeactivates
Copper peptides in same stepoxidation

Before you use it

Unstable — oxidizes to dehydroascorbic acid (orange/brown tint = expired). Use AM. Stable derivatives (ascorbyl glucoside, sodium ascorbyl phosphate) trade potency for shelf stability.

On the label

Look for "l-ascorbic acid" or "ascorbic acid" — not just "vitamin C". Dark glass or sealed pump packaging is non-negotiable. A clear or oxidised-looking serum means degraded product.

This guide is editorial, not medical advice. For a condition, a reaction or a medical question, see a dermatologist.