Cosmetics · Quasi-drug actives
Magnesium Ascorbyl Phosphate
アスコルビン酸リン酸Mg (Asukorubin-san rinsan magunesiumu)
Also known as: MAP
At a glance
| Category | Cosmetics |
|---|---|
| INCI name | Magnesium Ascorbyl Phosphate |
| Japanese labeling name | アスコルビン酸リン酸Mg |
| Common Japanese notations | アスコルビン酸リン酸Mg, リン酸アスコルビルマグネシウム |
| CAS number | 113170-55-1 |
| Origin | Synthetic (vitamin C derivative) |
| Typical functions | Quasi-drug whitening active, Antioxidant |
| Regulatory status in Japan | Approved as a quasi-drug (医薬部外品) whitening active by MHLW. |
Magnesium ascorbyl phosphate (MAP) is one of the established stable vitamin C derivatives used in Japanese cosmetics and quasi-drug whitening products. The phosphate conjugation stabilizes the ascorbate moiety against oxidation, with in vivo enzymatic conversion back to active vitamin C.
Classification
Tags below link to other ingredients sharing the same attribute, so you can pivot from one ingredient to its peers.
Product applications
Functions
Regulatory tags
Origin
Used in (typical product categories)
Finished-product categories that commonly include this ingredient in Japanese-market formulations.
- Medicated whitening products
- Brightening serums and lotions
- Anti-aging skincare
What it is
MAP is the magnesium salt of L-ascorbic acid 2-phosphate. The phosphate group at the C2 position protects ascorbate from oxidation; in vivo phosphatase enzymes can release the free ascorbate.
Typical uses in Japanese products
In Japanese cosmetics, MAP appears in medicated whitening products and brightening-positioned skincare across many brands.
Regulatory classification in Japan
Approved as a quasi-drug whitening active by MHLW.
Regulatory classification in other markets
| EU | Listed in CosIng. Permitted for cosmetic use. |
|---|---|
| USA | INCI recognized. |
| China | Permitted per IECIC listings. |
| Korea | Permitted under KFDA / MFDS. |
Example products
Example finished products will be added after each product's current full ingredient list has been verified.
All brand names and product names referenced anywhere on this site are the property of their respective owners. Example entries are provided for informational purposes only and do not imply endorsement.
Related ingredients
References
- Japan PMDA — quasi-drug active ingredient approval registry
- EU CosIng entry: Magnesium Ascorbyl Phosphate
Last updated: 2026-04-22. Ingredient entries are reviewed at least annually against current regulatory listings.