About
What it is and where it shows up.
Magnesium stearate is the magnesium salt of stearic acid, a long-chain saturated fatty acid derived from edible fats and oils. It is used in food manufacturing as a lubricant, release agent, anti-caking agent, and processing aid, particularly in tablet and capsule supplements and confectionery.
Safety summary
The regulatory and scientific consensus.
EFSA's 2018 re-evaluation concluded there is no need for a numerical ADI and that magnesium stearate (E470b) presents no safety concern at reported use levels. The substance dissociates in the gastrointestinal tract into fatty acid carboxylates and magnesium ions, which enter normal metabolic pathways. No concerns for mutagenicity or carcinogenicity were identified, though data on subchronic, chronic, and reproductive toxicity remain limited.
Regulatory landscape
What food-safety regulators have decided.
| Jurisdiction | Status | Note |
|---|---|---|
| FSANZ (Food Standards Australia New Zealand) (Australia) | Approved | Permitted as a food additive (emulsifier/food acid salt) under Food Standards Code Schedule 1; not considered to pose an unreasonable risk to public health according to NICNAS assessment of fatty acid salts including magnesium stearate.source |
| EFSA (European Food Safety Authority) (European Union) | Approved | Listed in the Codex General Standard for Food Additives (GSFA) as INS 470(iii) — Magnesium stearate. JECFA assessed in 1974 and considered myristic, palmitic, and stearic acid and their salts as normal products of fat metabolism with a well-established metabolic fate.source |
| FSSAI (Food Safety and Standards Authority of India) (India) | Approved | Listed as a permitted processing aid (INS 470(iii)) with polishing agent function, restricted to confectionery, at GMP residue levels under FSS (Food Products Standards and Food Additives) Regulations, 2011.source |
| FDA (Food and Drug Administration) (United States) | Approved | Affirmed GRAS as a direct human food ingredient under 21 CFR § 184.1440; permitted uses include lubricant/release agent, nutrient supplement, and processing aid at GMP levels.source |
Who should approach with care
Whose guidance would steer them away.
Kidney Disease — Magnesium stearate dissociates to release free magnesium ions in the GI tract; individuals with impaired renal function may have reduced ability to excrete excess magnesium, though intakes from food-additive use are generally very low relative to therapeutic magnesium doses.
Infants — EU Regulation (EC) No 1333/2008 restricts or excludes the use of many food additives including E470b from foods specifically manufactured for infants and young children; parents should verify product labels for this group.
Research citations
The sources behind this verdict.
- 1other. FAO GSFA Online — Magnesium stearate (INS 470(iii)). fao.org
- 2FDA. 21 CFR 184.1440 – Magnesium Stearate (Direct Food Substances Affirmed as Generally Recognized as Safe). accessdata.fda.gov
- 3PubMed. Magnesium stearate, a widely-used food additive, exhibits a lack of in vitro and in vivo genotoxic potential. pmc.ncbi.nlm.nih.gov
- 4WHO. JECFA Food Additives and Contaminants Database – Magnesium stearate (chemID 4275). apps.who.int
- 5FDA. FDA HFP Food Substances Database — Magnesium Salts of Fatty Acids (21 CFR § 184.1440). hfpappexternal.fda.gov
- 6FSSAI. Active List of Processing Aids Allowed for Use by Food Business Operators under FSS (FPS&FA) Regulations, 2011 – Direction under Section 16(5), 2024.
Independently researched8 citations