NAV

Evening primrose oil

Identification

Generic Name
Evening primrose oil
DrugBank Accession Number
DB11358
Background

Evening primrose oil comes from the extraction from Oenothera biennis seeds and it is commonly used as an alternative source for omega-6 essential fatty acids. In its composition it presents some fatty acids such as Linolenic acid and Gamolenic acid.1 Evening primrose oil has been filled for the FDA by Humanetics Corporation on April 2000 to be a new dietary ingredient but its current status is "Inadequate basis for expectation of safety".5 By Health Canada, evening primrose oil is approved in over-the-counter combination dietary supplements.6 By the EMA, evening primrose oil is approved in herbal preparations.7

Type
Biotech
Groups
Investigational, Nutraceutical
Synonyms
  • Oenothera biennis (evening primrose) oil
  • Oenothera biennis (evening primrose) seed extract
  • Oenothera biennis l. oil
  • Oenothera biennis seed extract
  • Oenothera biennis seed oil
  • Oenothera lamarckiana l. oil
  • Oenothera muricata seed oil
  • Oenothera oil
  • Oenothera pycnocarpa seed oil
  • Oenotherae biennis oleum
  • Oils, glyceridic, evening primrose
  • Oleum oenotherae erythrospinae
  • Primrose oil
Poor quality drug data slowing you down?
Unlock 38% more drug discovery time and eliminate decision-making doubts with this one-stop guide to quality drug data.
Download eBook
Poor quality drug data slowing you down?
Download eBook

Pharmacology

Indication

Evening primrose oil is used as part of over-the-counter dietary supplements.6

It is also used for the treatment of systemic inflammatory diseases and for women's health conditions such as cyclical mastalgia. These indications do not have sufficient evidence of their effectiveness. It was used for the treatment of atopic dermatitis in the United Kingdom but it is currently withdrawn due to lack of evidence of effectiveness.1

Reduce drug development failure rates
Build, train, & validate machine-learning models
with evidence-based and structured datasets.
See how
Build, train, & validate predictive machine-learning models with structured datasets.
See how
Associated Therapies
Contraindications & Blackbox Warnings
Prevent Adverse Drug Events Today
Tap into our Clinical API for life-saving information on contraindications & blackbox warnings, population restrictions, harmful risks, & more.
Learn more
Avoid life-threatening adverse drug events with our Clinical API
Learn more
Pharmacodynamics

The effectivity of evening primrose oil is debatable as the evidence is very limited.9 Evening primrose oil improves the essential fatty acid content in plasma, erythrocyte, and platelet lipids. It has also been registered to increase alpha-tocopherol levels in non-diabetic and type I diabetic patients. Evening primrose oil affects the fatty acid composition of serum lipids and adipose tissue as well as it helps maintain normal cellular structures and it serves as a prostaglandin precursor. Administration of evening primrose oil is part of long-term therapy and thus, immediate results are never expected.4

Mechanism of action

Evening primrose oil presents a content of 74% Linolenic acid and 9% Gamolenic acid from which the later seems to be the key active ingredient of this oil. These major essential fatty acids are required for the normal structure of cell membranes and they are not synthesized endogenously.4 The therapeutic activity of evening primrose oil is attributed to the direct action of its essential fatty acids on immune cells as well as to an indirect effect on the synthesis of eicosanoids. The actions of highly unsaturated fatty acids in tissues and eicosanoids are thought to be implicated in inflammatory and immunologic pathogeneses.1

The essential fatty acids found in evening primrose oil are involved in the biosynthesis of prostaglandin. For this activity, the main involved component is the Gamolenic acid. The presence of this essential fatty acid allows the synthesis of anti-inflammatory substances such as 15-hydroxy-eicosatrienoic acid and prostaglandin E1.4

Absorption

The pharmacokinetics of evening primrose oil is mainly studied by analyzing its active ingredient Gamolenic acid. After administration, Gamolenic acid is rapidly absorbed and converted directly to Dihomo-gamma-linolenic acid and other precursors.4 When orally administered, the tmax was directly dependent to the time of administration, being of 2.7 hours in the evening and 4.4 hours in the morning. The Cmax and AUC were registered to be approximately 21 mcg/ml and 274 mcg.h/ml.2 The bioavailability of Gamolenic acid acid is influenced by triglyceride composition, cellular kinetics of phospholipases and acyltransferases.3

Volume of distribution

No pharmacokinetic data available.

Protein binding

No pharmacokinetic data available.

Metabolism

The main component of evening primrose oil, Linolenic acid is usually desaturated by delta-6-desaturase which transforms this fatty acid to Gamolenic acid. This metabolic activity usually is limited by external factors such as stress, aging, alcohol, smoking, inflammation, diabetes, etc. In presence of these circumstances, the linoleic acid gets accumulated in the body and it inhibits the activity of the enzyme delta-6-desaturase. In proper conditions, Gamolenic acid forms Dihomo-gamma-linolenic acid by the action of elongases and it can further act as a substrate for production of prostaglandins or to be denaturated to arachidonic acid.4

Hover over products below to view reaction partners

Route of elimination

The major components of the primrose oil are highly metabolized and the majority of the generated metabolites are excreted in the urine.8

Half-life

No pharmacokinetic data available.

Clearance

No pharmacokinetic data available.

Adverse Effects
Improve decision support & research outcomes
With structured adverse effects data, including: blackbox warnings, adverse reactions, warning & precautions, & incidence rates. View sample adverse effects data in our new Data Library!
See the data
Improve decision support & research outcomes with our structured adverse effects data.
See a data sample
Toxicity

Evening primrose oil seems to have little toxicological effect in humans. The reported LD50 values in the mouse are 3.12 x 10^4 mcg/kg. The toxicological effects are very minimal and it has proven to not have an effect on tumor incidence nor to present effects on fertility studies.9

Pathways
Not Available
Pharmacogenomic Effects/ADRs
Not Available

Interactions

Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
DrugInteraction
Integrate drug-drug
interactions in your software
AbacavirAbacavir may decrease the excretion rate of Evening primrose oil which could result in a higher serum level.
AceclofenacAceclofenac may decrease the excretion rate of Evening primrose oil which could result in a higher serum level.
AcemetacinAcemetacin may decrease the excretion rate of Evening primrose oil which could result in a higher serum level.
AcetaminophenAcetaminophen may decrease the excretion rate of Evening primrose oil which could result in a higher serum level.
AcetazolamideThe therapeutic efficacy of Acetazolamide can be decreased when used in combination with Evening primrose oil.
Food Interactions
Not Available

Products

Drug product information from 10+ global regions
Our datasets provide approved product information including:
dosage, form, labeller, route of administration, and marketing period.
Access now
Access drug product information from over 10 global regions.
Access now
Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
Efamol CapEvening primrose oil (.6 mL) + Vitamin E (13.6 unit)CapsuleOralEfamol Research Inc.1982-12-311999-10-25Canada flag
Evening Primrose Oil CapEvening primrose oil (500 mg / cap) + Vitamin E (13.6 unit / cap)CapsuleOralNature's Way Of Canada Ltd.1984-12-312004-07-26Canada flag
Evening Primrose Oil With Vitamin EEvening primrose oil (500 mg/1) + Vitamin E (15 unit/1)CapsuleOralAshbury Research CorporationNot applicableNot applicableCanada flag
Gamma OilEvening primrose oil (500 mg / cap) + Vitamin E (14.9 unit / cap)CapsuleOralQuest Vitamins A Div Of Purity Life Health Products1985-12-312000-07-20Canada flag
Hovid Omega-3 + 6Evening primrose oil (500 mg) + Fish oil (500 mg)Capsule, gelatin coatedOralHovid Berhad2020-09-08Not applicableMalaysia flag
Unapproved/Other Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
Rhodd Ato Repair Body So ApEvening primrose oil (6.0 g/100g) + Chamaecyparis obtusa leaf (2.0 g/100g) + Olive oil (13.0 g/100g)SoapTopicalSJ NATURAL2018-08-01Not applicableUS flag
VP-PrecipEvening primrose oil (500 mg/1) + Bilberry (40 mg/1) + Linseed oil (1000 mg/1)Capsule, gelatin coatedOralVirtus Pharmaceuticals2012-05-182016-03-03US flag

Categories

Drug Categories
Classification
Not classified
Affected organisms
  • Humans and other mammals

Chemical Identifiers

UNII
3Q9L08K71N
CAS number
308064-97-3

References

General References
  1. Bayles B, Usatine R: Evening primrose oil. Am Fam Physician. 2009 Dec 15;80(12):1405-8. [Article]
  2. Martens-Lobenhoffer J, Meyer FP: Pharmacokinetic data of gamma-linolenic acid in healthy volunteers after the administration of evening primrose oil (Epogam). Int J Clin Pharmacol Ther. 1998 Jul;36(7):363-6. [Article]
  3. Fan YY, Chapkin RS, Ramos KS: Dietary lipid source alters murine macrophage/vascular smooth muscle cell interactions in vitro. J Nutr. 1996 Sep;126(9):2083-8. doi: 10.1093/jn/126.9.2083. [Article]
  4. Wollschlaeger B. (2003). The ABC Clinical Guide to Herbs. American botanical council.
  5. FDA new dietary ingredients [Link]
  6. Health Canada [Link]
  7. EMA [Link]
  8. Gamma-linolenic acid monograph [File]
  9. Chemical Information Document of the National Toxicology Program [File]
PubChem Substance
347911198
RxNav
1437503
Wikipedia
Oenothera_biennis
MSDS
Download (46.8 KB)

Clinical Trials

Clinical Trials
PhaseStatusPurposeConditionsCount
4CompletedTreatmentAtopic Dermatitis / Neurodermatitis1
4CompletedTreatmentBenign Breast Disease / Breast Pain / Fibroadenoma / Fibrocystic Disease of Breast1
4CompletedTreatmentMissed Abortion1
3Unknown StatusTreatmentMissed Abortion1

Pharmacoeconomics

Manufacturers
Not Available
Packagers
Not Available
Dosage Forms
FormRouteStrength
CapsuleOral450 mg
CapsuleOral1000 MG
Capsule, liquid filledOral
Capsule, gelatin coatedOral500 mg
Capsule, gelatin coatedOral
CapsuleOral
CapsuleOral
CapsuleOral1300 mg
SoapTopical
Capsule, liquid filledOral
Capsule, gelatin coatedOral1000 MG
Oil1000 mg
Capsule, gelatin coatedOral
TabletOral
Prices
Not Available
Patents
Not Available

Properties

State
Liquid
Experimental Properties
PropertyValueSource
boiling point (°C)240 ºC'MSDS'
water solubilityInsoluble'MSDS'

Enzymes

Details1. Elongation of very long chain fatty acids protein 5
Kind
Protein
Organism
Humans
Pharmacological action
No
Actions
Ligand
General Function
Catalyzes the first and rate-limiting reaction of the four that constitute the long-chain fatty acids elongation cycle. This endoplasmic reticulum-bound enzymatic process, allows the addition of 2 carbons to the chain of long- and very long-chain fatty acids/VLCFAs per cycle. Condensing enzyme that acts specifically toward polyunsaturated acyl-CoA with the higher activity toward C18:3(n-6) acyl-CoA. May participate in the production of monounsaturated and of polyunsaturated VLCFAs of different chain lengths that are involved in multiple biological processes as precursors of membrane lipids and lipid mediators.
Specific Function
3-oxo-arachidoyl-coa synthase activity
Gene Name
ELOVL5
Uniprot ID
Q9NYP7
Uniprot Name
Elongation of very long chain fatty acids protein 5
Molecular Weight
35293.15 Da
References
  1. Timoszuk M, Bielawska K, Skrzydlewska E: Evening Primrose (Oenothera biennis) Biological Activity Dependent on Chemical Composition. Antioxidants (Basel). 2018 Aug 14;7(8). pii: antiox7080108. doi: 10.3390/antiox7080108. [Article]
  2. Wollschlaeger B. (2003). The ABC Clinical Guide to Herbs. American botanical council.
Details2. Fatty acid desaturase 1
Kind
Protein
Organism
Humans
Pharmacological action
No
Actions
Ligand
General Function
Oxidoreductase activity
Specific Function
Isoform 2 does not exhibit any catalytic activity toward 20:3n-6, but it may enhance FADS2 activity (By similarity). Isoform 1 is a component of a lipid metabolic pathway that catalyzes biosynthesi...
Gene Name
FADS1
Uniprot ID
O60427
Uniprot Name
Fatty acid desaturase 1
Molecular Weight
51963.945 Da
References
  1. Timoszuk M, Bielawska K, Skrzydlewska E: Evening Primrose (Oenothera biennis) Biological Activity Dependent on Chemical Composition. Antioxidants (Basel). 2018 Aug 14;7(8). pii: antiox7080108. doi: 10.3390/antiox7080108. [Article]
  2. Wollschlaeger B. (2003). The ABC Clinical Guide to Herbs. American botanical council.
Details3. Fatty acid desaturase 2
Kind
Protein
Organism
Humans
Pharmacological action
Unknown
Actions
Ligand
General Function
Stearoyl-coa 9-desaturase activity
Specific Function
Component of a lipid metabolic pathway that catalyzes biosynthesis of highly unsaturated fatty acids (HUFA) from precursor essential polyunsaturated fatty acids (PUFA) linoleic acid (LA) (18:2n-6) ...
Gene Name
FADS2
Uniprot ID
O95864
Uniprot Name
Fatty acid desaturase 2
Molecular Weight
52259.075 Da
References
  1. Timoszuk M, Bielawska K, Skrzydlewska E: Evening Primrose (Oenothera biennis) Biological Activity Dependent on Chemical Composition. Antioxidants (Basel). 2018 Aug 14;7(8). pii: antiox7080108. doi: 10.3390/antiox7080108. [Article]
  2. Wollschlaeger B. (2003). The ABC Clinical Guide to Herbs. American botanical council.

Drug created at December 03, 2015 16:52 / Updated at September 28, 2021 21:54