Nordihydroguaiaretic acid (NDGA)
500-38-9 · .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'-[2,3-Dimethyl-1,4-butanediyl]-bis[1,2-benzenediol · 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 · 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] · Nordihydroguaiaretic acid (NDGA)CAS 500-38-9
Listed as an antioxidant by the US.
Listed as antioxidants (US)
- United States: Antioxidant — FDA, Substances Added to Food: NORDIHYDROGUAIARETIC ACID--PROHIBITED WITH EXCEPTIONS
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
| Jurisdiction | Status | Scope and limits | Citation |
|---|---|---|---|
| Australia and New Zealand | No listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it. | ||
| Canada | No listing matchedHealth Canada’s lists name additives without E or INS numbers, so this site matches them by exact name. A substance listed there under a name this site does not recognise has no row here. | ||
| European Union | No listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it. | ||
| Great Britain | No listed food uses foundThis site has not matched this substance to any food use on this jurisdiction’s list of authorised food additives. A food additive may be used only in foods that list names. Flavourings, enzymes, processing aids and added nutrients are regulated separately and do not appear on it. | ||
| Japan | No listing matchedThis site imports only Japan’s list of designated additives (Appended Table 1 to the Regulations for Enforcement of the Food Sanitation Act), matched by English name. Existing additives, natural flavouring agents and ordinary foods used as additives are permitted outside that list and are not imported, so an empty row does not show that Japan does not permit the substance. | ||
| South Korea | No listing matchedThis site imports Part III of South Korea’s Standards and Specifications for Food Additives, matched by CAS number, then INS number, then exact name. Mixed preparations and sanitisers are not imported, and an entry whose identifiers disagreed with a page’s is held for review, so an empty row does not show that South Korea does not permit the substance. | ||
| United States | Prohibited | 21 CFR 189.165retrieved 2026-10-17 | |
| Codex Alimentarius | Not 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
Compare other additives on the dietary indexes.
- CAS registry number
- 500-38-9
- InChIKey
- HCZKYJDFEPMADG-UHFFFAOYSA-N
- PubChem
- CID 4534
How JECFA defines it
The international specification for identity and purity, prepared by the Joint FAO/WHO Expert Committee on Food Additives and published by FAO. It is a different document from any above, written by a different body and revised on its own cycle; it is advisory, and a country adopts it or does not.
Nordihydroguaiaretic Acid
Synonyms: NDGA
Assay, identification and purity criteria
Description and assay
- Specification history
- Prepared at the 17th JECFA (1973), published in FNP 4 (1978) and in FNP 52 (1992). Metals and arsenic specifications revised at the 63rd JECFA (2004). No ADI was allocated at the 17th JECFA (1973)
- Chemical names
- 4,4'-(2,3-Dimethyltetramethylene)-dipyro-catechol; 1,4-dipyro-catechol-2,3-dimethyl-butane; nordihydroguaiaretic acid; ß,gamma -dimethyl-alpha,delta-bis(3,4-dihydroxyphenyl) butane
- C.A.S. number
- 500-38-9
- Chemical formula
- C 18 H 22 O 4
- Formula weight
- 302.36
- Assay
- Not less than 95% and not more than 102%
- DESCRIPTION
- White to greyish-white crystalline solid and may be prepared from the evergreen desert shrub, Larrea divaricata , (Fam. Zygophyllaceae )
- FUNCTIONAL USES
- Antioxidant
- METHOD OF ASSAY
- Weigh 1.00 g of the sample. Dilute with methanol so that the final concentration will be 1 mg of the sample per 100 ml of solution. Read the absorbance at 284 nm in a 1 cm quartz cell. Calculate the % nordihydroguaiaretic acid from: where a = the obtained absorbance W = the weight of the sample
Identification
- Solubility (Vol. 4)
- Freely soluble in ethanol and ether, and in propylene glycol at 116 o
- Melting point (Vol. 4)
- About 184 o
- Colour reactions
- Passes test See description under TESTS
- Test: Colour reactions
- Add 2 ml of ferric chloride TS, ethanolic and 2 ml of 0.2% of 2,2'-bipyridine in absolute ethanol to 5 ml of 0.5% solution of the sample in 50% ethanol. A deep cherry-red colour appears To 5 ml of 1% solution of the sample in 75% ethanol, add 1 ml of strong ammonia TS. A yellow colour develops To 10 ml of 0.5% solution of the sample in 50% ethanol, add 1.5 ml of 1% barium hydroxide (Ba(OH) 2 · H 2 O) in boiled water. A deep blue colour develops which is stable for approximately 1 h To 10 ml of 10% sodium hydroxide, add 1 ml of 0.5% solution of the sample in 50% ethanol. A rose-red colour develops
Purity criteria
- Lead (Vol. 4)
- Not more than 2 mg/kg Determine using an atomic absorption technique appropriate to the specified level. The selection of sample size and method of sample preparation may be based on the principles of the method described in Volume 4, “Instrumental Methods.”
Every name it appears under
55 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'-[2,3-Dimethyl-1,4-butanediyl]-bis[1,2-benzenediol
- 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
| Type | Value | Population | Assessed by | Opinion |
|---|---|---|---|---|
| ADI | not allocated | — | JECFA | 1973 |
Evidence and how bodies read it
Studies, and the differing conclusions regulators drew from them, are curated rather than machine-read, and none has been written for this substance yet.
Common questions
Assembled from what is above, in the words the questions are usually asked in. Each answer is the same statement the relevant section makes, with the same citations behind it.
- What is 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.
- What is Nordihydroguaiaretic acid (NDGA) used for in food?
- It is listed as an antioxidant — the role the US assigns it. This page shows every function each regulator records, with the citation for each.
- Is Nordihydroguaiaretic acid (NDGA) vegan?
- Yes. Nordihydroguaiaretic acid (NDGA) is not derived from animals, and is suitable for vegetarians. This page says what it is made from and how.
Sources for this page
- ecfr retrieved 2026-10-17
- jecfaspecs retrieved 2026-09-23
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