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Magnesium Ascorbyl Phosphate: does it work, and at what %?
Magnesium Ascorbyl Phosphate is one of the actives we grade on evidence, not marketing. The benefit is real — but only when the dose clears the threshold the research supports. Here's the number, and the products that actually hit it.
The verdict: A stable vitamin C derivative that brightens at gentler concentrations than L-ascorbic acid.
How we grade Magnesium Ascorbyl Phosphate
We check the disclosed concentration against the effective threshold from peer-reviewed dermatology literature and regulatory monographs, then weigh the formulation and any product-specific study. The grade is computed from the open rubric — re-run it on any ingredient list and you get the same letter. Also labeled as MAP, Vitamin C derivative.
Products with a disclosed effective dose
We haven't yet graded a product that discloses an effective dose of Magnesium Ascorbyl Phosphate — most brands won't publish the concentration. As brands disclose (or get Verified), graded products will appear here. Browse the full index →
Common questions
What concentration of Magnesium Ascorbyl Phosphate is effective?
On Visage Theory's rubric, Magnesium Ascorbyl Phosphate reaches an effective dose at 3% and a strong, research-backed dose at 10%. Below that, the labeled benefit is unlikely no matter how good the marketing is.
Is more Magnesium Ascorbyl Phosphate always better?
Not necessarily — past the effective range you mostly add irritation risk, not benefit. What matters is clearing the threshold in a stable formula, which is exactly what our grade checks.
How do I know a product actually contains an effective dose of Magnesium Ascorbyl Phosphate?
Most brands list the active but hide the concentration. When the dose isn't disclosed we can't confirm efficacy, so we withhold a grade rather than guess. Products that disclose an effective dose are graded and listed below.
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