Nordihydroguaiaretic acid (NDGA)

NDGA is an antioxidant obtained from the creosote bush and was used to stop fats going rancid. The FDA removed it from the GRAS list and prohibited it after animal studies reported kidney damage.

Where it is and isn’t permitted

Status of Nordihydroguaiaretic acid (NDGA) by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationProhibited21 CFR 189.165retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFANot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.

What it is made from

Extracted from the leaves and twigs of the creosote bush, Larrea tridentata, of the south-western United States and Mexico. It can also be synthesised.

  • Vegan
  • Vegetarian
InChIKey
HCZKYJDFEPMADG-UHFFFAOYSA-N
PubChem
CID 4534

Every name it appears under

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

CAS registry number

  • 500-38-9

As it appears in regulation

  • Nordihydroguaiaretic acid (NDGA)

Other names

  • .beta.,.delta.-bis(3,4-dihydroxyphenyl)butane
  • .beta.,.gamma.-Dimethyl-.alpha.,.delta.-bis(3,4-dihydroxyphenyl)butane
  • 1, 4,4'-(2,3-dimethyl-1,4-butanediyl)bis-
  • 1,2-Benzenediol, 4,4'-(2,3-dimethyl-1,4-butanediyl)bis-
  • 1,4-Bis(3,4-dihydroxyphenyl)-2,3-dimethyl-butan
  • 2,3-bis(3,4-dihydroxybenzyl)butane
  • 2,3-Bis(3,4-dihydroxyphenylmethyl)butane
  • 2,3-Dimethyl-1,4-bis(3,4-dihydroxyphenyl)butane
  • 4,3-Dimethyl-1,4-butanediyl)bis(pyrocatechol)
  • 4,3-Dimethyltetramethylene)dipyrocatechol
  • 4,4'-(2,3-Dimethyl-1,4-butanediyl)bis(pyrocatechol)
  • 4,4'-(2,3-Dimethyl-1,4-butanediyl)bis-1,2-benzenediol
  • 4,4'-(2,3-dimethylbutane-1,4-diyl)bis(benzene-1,2-diol)
  • 4,4'-(2,3-Dimethylbutane-1,4-diyl)di(benzene-1,2-diol)
  • 4,4'-(2,3-dimethylbutane-1,4-diyl)dibenzene-1,2-diol
  • 4,4'-(2,3-Dimethyltetramethyl-ene)dipyrocatechol
  • 4,4'-(2,3-Dimethyltetramethylene)dipyrocatechol
  • 4-[4-(3,4-dihydroxyphenyl)-2,3-dimethyl-butyl]benzene-1,2-diol
  • 4-[4-(3,4-dihydroxyphenyl)-2,3-dimethyl-butyl]pyrocatechol
  • 4-[4-(3,4-dihydroxyphenyl)-2,3-dimethylbutyl]benzene-1,2-diol
  • 4-[4-[3,4-bis(oxidanyl)phenyl]-2,3-dimethyl-butyl]benzene-1,2-diol
  • beta,gamma-Dimethyl-alpha,delta-bis(3,4-dihydroxyphenyl)butane
  • Butane, 1,4-bis(3,4-dihydroxyphenyl)-2,3-dimethyl-
  • Butane,4-bis(3,4-dihydroxyphenyl)-2,3-dimethyl-
  • CAS-500-38-9
  • CCRIS 1399
  • CHX 100; Masoprocol; meso-NDGA
  • Dinorguaia
  • HCZKYJDFEPMADG-UHFFFAOYSA-
  • HMS503G19
  • LOX inhibitor, N/A
  • NDGA
  • Nordihydro Guaiaretic Acid (mixture of diastereomers)
  • nordihydroguaiaretate
  • NORDIHYDROGUAIARETIC ACID
  • nordihydroguaiaretic acid (ndga)
  • Nordihydroguaiaretic acid (Standard)
  • Nordihydroguaiaretic acid - mixture of diastereomers
  • Nordihydroguaiaretic acid, >=90% (HPLC), from Larrea divaricata (creosote bush)
  • Nordihydroguaiaretic acid, >=97.0% (HPLC)
  • NordihydroGuaiareticAcid-d6
  • nordihydroguajaretic acid
  • nordihydroguaretic acid
  • Norguaiaretic acid, dihydro
  • Norguaiaretic acid, dihydro-
  • Norhydroguaiaretic acid
  • Pyrocatechol, 4,4'-(2,3-dimethyltetramethylene)di-
  • PYROCATECHOL,4'- (2,3-DIEMTHYLTETRAMETHYLENE) DI-
  • Pyrocatechol,4'-(2,3-dimethyltetramethylene)di-
  • WLN: QR BQ D1Y1&Y1&1R CQ DQ

Systematic names

  • InChI=1/C18H22O4/c1-11(7-13-3-5-15(19)17(21)9-13)12(2)8-14-4-6-16(20)18(22)10-14/h3-6,9-12,19-22H,7-8H2,1-2H3
  • Nordihydroguaiaretic acid; 4,4'-(2,3-Dimethyl-1,4-butanediyl)bis[1,2-benzenediol]

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

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

Machine-readable:/api/v1/additives/nordihydroguaiaretic-acid-ndga.json