Magnesium stearate

INS 470(iii)CAS 557-04-0

Used as an emulsifier — Codex also lists it as anticaking agent, thickener.

Magnesium stearate is best known as a tablet lubricant but is also used in food as an anticaking agent and emulsifier, notably in confectionery and powdered products.

Where it is and isn’t permitted

Status of Magnesium stearate by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted21 CFR 184.1440retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFAPermitted, with conditions

1 food category

no numerical limit (good manufacturing practice)

CXS 192-1995 Table Three, INS 470(iii)and 1 further provisionretrieved 2026-09-07

What it is made from

Made by reacting stearic acid with a magnesium salt. The stearic acid may be of plant or animal origin; pharmaceutical grades are often declared vegetable, food grades usually are not.

  • Vegan status depends on the source
  • Vegetarian status depends on the source
  • May raise a halal question
  • May raise a kosher question

This is not an omission. What this additive is made from is not fixed — depending on the manufacturer it may be plant, animal or microbial in origin, nobody is required to say which, and the same product can change source between production runs. Ask the manufacturer if it matters to you; a label cannot answer it.

CAS registry number
557-04-0
InChIKey
HQKMJHAJHXVSDF-UHFFFAOYSA-L
PubChem
CID 11177

Every name it appears under

26 recorded names. A label may use any of them.

INS number

  • 470(iii)

CAS registry number

  • 557-04-0

As it appears in regulation

  • Magnesium stearate

Other names

  • C36H70MgO4
  • DAYCLING
  • Dibasic magnesium stearate
  • HSDB 713
  • Magnesii stearas
  • magnesium dioctadecanoate
  • Magnesium distearate
  • Magnesium distearate, pure
  • Magnesium octadecanoate
  • MAGNESIUM STEARATE
  • Magnesium stearate (JP17/NF)
  • Magnesium stearate g
  • Magnesium stearate, tech
  • magnesium(ii) stearate
  • NS-M (salt)
  • Octadecanoic acid, magnesium salt
  • Octadecanoic acid, magnesium salt (2:1)
  • Petrac MG 20NF
  • stearatedemagnesium
  • Stearic Acid Magnesium(II) Salt
  • Stearic acid, magnesium salt
  • Synpro 90
  • Synpro Magnesium Stearate 90

Hazard reference values

No reference value for this substance in the sources we hold.

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • ecfr retrieved 2026-09-07
  • gsfa retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/magnesium-stearate.json