Magnesium Ascorbyl Phosphate
Another stable, water-soluble derivative that converts to active Vitamin C in the skin. Slightly more hydrating than SAP and considered one of the mildest forms available, making it common in drugstore and sensitive-skin formulas.
Typical concentration
3–10%
Formulation pH
6–7
What MAP is used for
- Very gentle, low irritation potential
- Some added hydrating benefit
- Helps with mild brightening and dullness
Stability
Stable at neutral-to-slightly-acidic pH; more shelf-stable than L-Ascorbic Acid but conversion efficiency in skin is debated.
Advantages
- Extremely gentle
- Suitable for reactive or rosacea-prone skin
- Good shelf life
Limitations
- Lower potency and slower visible results
- Limited clinical evidence at cosmetic concentrations
Commonly paired with
Use with care alongside
How MAP compares with other vitamin C forms
| Form | Typical concentration | pH |
|---|---|---|
| L-Ascorbic Acid | 8–20% (10–15% is the effective, well-tolerated sweet spot for most skin types) | Below 3.5 for optimal skin penetration |
| Sodium Ascorbyl Phosphate | 5–15% | 6–7 (near neutral) |
| Magnesium Ascorbyl Phosphate | 3–10% | 6–7 |
| Tetrahexyldecyl Ascorbate | 5–20% | Flexible, works across a wide pH range |
| Ascorbyl Glucoside | 10–25% | 5–7 |
| 3-O-Ethyl Ascorbic Acid | Retail serums commonly list 10–15%. There is no well-established optimum from independent clinical studies, and percentages are not directly comparable with L-ascorbic acid. | Does not need the very low pH that L-ascorbic acid does; formulas are usually mildly acidic |
Serums using Magnesium Ascorbyl Phosphate
Magnesium Ascorbyl Phosphate: quick answers
+What is Magnesium Ascorbyl Phosphate?
Another stable, water-soluble derivative that converts to active Vitamin C in the skin. Slightly more hydrating than SAP and considered one of the mildest forms available, making it common in drugstore and sensitive-skin formulas.
+What concentration of Magnesium Ascorbyl Phosphate is typical?
3–10%
+What pH does Magnesium Ascorbyl Phosphate need?
6–7
+How stable is Magnesium Ascorbyl Phosphate?
Stable at neutral-to-slightly-acidic pH; more shelf-stable than L-Ascorbic Acid but conversion efficiency in skin is debated.
Who it may suit
Related guides
Sources
- Al-Niaimi F, Chiang NYZ. Topical Vitamin C and the Skin: Mechanisms of Action and Clinical Applications. J Clin Aesthet Dermatol, 2017.
- Telang PS. Vitamin C in dermatology. Indian Dermatology Online Journal, 2013.
- Pinnell SR et al. Topical L-ascorbic acid: percutaneous absorption studies. Dermatologic Surgery, 2001.
We are not dermatologists and this page has not been medically reviewed. It is for information only — consult a qualified professional before making decisions about your skin.