Evening primrose
Oenothera biennis L.Onagraceae // seed oil
Overview
Plant parts
seed oil
Known constituents
gamma-linolenic acid, linoleic acid
Research corpus coverage
Chemistry notes
- CHEMISTRY: Relevant reported constituents include gamma-linolenic acid; linoleic acid; constituent presence alone does not establish clinical efficacy.
Uses & Evidence
Traditional / historical use
Documented traditional use — not a claim of established efficacy.
TRADITIONAL: Evening primrose has been used for eczema; breast pain; PMS; this records historical/traditional use and does not establish efficacy.
MODERATE · evidence synthesis/fact sheet · NCCIH Herbs at a Glance
Modern evidence
EVIDENCE: For the major use set (eczema; breast pain; PMS), the evidence assessment is contradicted: Contradicted/insufficient for eczema in systematic reviews; limited/mixed for breast pain and PMS.
HIGH · systematic review/meta-analysis · NCCIH Herbs at a Glance
Preparation
Forms used traditionally
A listed form does not imply it suits every plant part, or that one preparation is interchangeable with another — see the plant’s own notes below.
PREPARATION: The medicinal material is seed oil; traditional and modern forms include infusion/tea, tincture, powder/capsule, extract. No dose or potency is specified.
MODERATE · regulatory monograph · EMA European Union herbal monographs and list entries
Preparation-specific evidence should not be generalized across extracts, teas, oils, or whole herb.
Safety
Additional safety notes (general, unstructured)
Free-text safety notes carried from their source — not broken out by species, route, or hazard type, and not equivalent to the structured records above. Each note names the kind of source it came from.
SAFETY: Major issues include GI upset; headache; possible seizure concern. Contraindications/cautions include Seizure disorders.
HIGH · evidence synthesis/fact sheet · NCCIH Herbs at a Glance
SAFETY: Clinically relevant interaction concerns include Potential additive bleeding; caution with phenothiazines and seizure-threshold-lowering drugs.
MODERATE · evidence synthesis/fact sheet · NCCIH Herbs at a Glance
Some interactions are theoretical or based on case reports/pharmacokinetics rather than outcome trials.
SAFETY: Pregnancy/lactation reference: Insufficient pregnancy/lactation evidence.
MODERATE · regulatory monograph or evidence synthesis · NCCIH Herbs at a Glance
Absence of evidence is not evidence of safety.
Preparation × species risk matrix
Unknown means insufficient evidence was located — not that a form is safe.
Cats
- tinctureCaution
- concentrated extractUnknown
- essential oilUnknown
- glyceriteUnknown
- infused oilUnknown
- salveUnknown
- smoke/combustionUnknown
- tea/infusionUnknown
- whole herbUnknown
Dogs
- tinctureCaution
- concentrated extractUnknown
- essential oilUnknown
- glyceriteUnknown
- infused oilUnknown
- salveUnknown
- smoke/combustionUnknown
- tea/infusionUnknown
- whole herbUnknown
Identity
Botanical synonym
Onagra biennis (L.) Scop.
Taxonomic identity note
- Evening primrose is treated here as Oenothera biennis L. in the family Onagraceae; recorded older names include Onagra biennis (L.) Scop..
Sources
Research records are source-linked but may not yet be editorially reviewed.
- NCCIH Herbs at a Glance5 claims
NCCIH fact sheet
- Plants of the World Online1 claim
botanical taxonomy database
EMA monograph
WHO monograph