Oenothera biennis · PhytoNexus

01 Identity and provenance

Accepted binomial: Oenothera biennis
Common names: Evening Primrose
Family (APG IV): Onagraceae
Part used: Seed
Verification tier: Tier 2 · Verified Clinical columns reviewed and a source is on record.
Reviewer note (2026 audit): Reference not supplied - claim unverified against primary literature.

02 Constituent chemistry

Chemical class	Marker compound	Synthetic analogue in use
Gamma linolenic acid, Linolenic acid, Oleic Acid	Gamma linolenic acid Seed	Omega3 fatty acid ethyl esters

The analogue column is what makes the interaction reasoning tractable: where a constituent has a marketed structural counterpart, the counterpart's interaction profile is the starting hypothesis for the plant.

Looking up structures and physicochemical properties from PubChem…

03 Stated application

Reported activity: Eczema, Rheumatoid arthritis,
Diabetic neuropathy
Marketed in: Oil: Efamol evening primrose oil,Nature's bounty evening oil
Reported adverse effects: Nausea, Diarrhea, Headache, Increased bleeding risk

04 Interaction matrix

Source column, verbatim: Anti-coagulant anti-platelet Anti-psychotic
Normalised onto 3 canonical drug classes below.

Curated from the reviewed source

Drug class	Severity	Mechanism type	Provenance	Expected effect
Anticoagulants (vitamin-K antagonists, DOACs) Haemostasis	3Major	PD-additive + PK-CYP2C9	curated B	INR destabilisation in either direction; ecchymosis, epistaxis, gum bleed…	why ▾
Class mechanism. Coumarin-, salicylate- and coumestan-bearing botanicals add to vitamin-K-antagonist effect; several also compete for CYP2C9 and CYP3A4, raising S-warfarin exposure. Botanicals rich in vitamin K1 act in the opposite direction and blunt anticoagulation. Expected INR destabilisation in either direction; ecchymosis, epistaxis, gum bleeding, GI or intracranial haemorrhage. Management Do not start or stop the botanical without INR cover. Check INR at 3-5 days and again at 2 weeks. Document the product, batch and dose in the anticoagulation record. Onset rapid Evidence B - reviewed clinical column, source pending Matched on “anti-coagulant” Find evidence for this pair Map this mechanism
Antiplatelet agents Haemostasis	3Major	PD-additive	curated B	Prolonged bleeding time, surgical and post-procedural bleeding, bruising,…	why ▾
Class mechanism. Organosulfur compounds, gingerols, salicylates, ginkgolides and eugenol inhibit thromboxane A2 synthesis, platelet aggregation and PAF-mediated activation, duplicating the pharmacology of aspirin and P2Y12 blockers. Expected Prolonged bleeding time, surgical and post-procedural bleeding, bruising, haematuria. Management Stop the botanical 7-14 days before elective surgery or neuraxial anaesthesia. Record it on the pre-operative medicines list. Onset rapid Evidence B - reviewed clinical column, source pending Matched on “anti-platelet” Find evidence for this pair Map this mechanism
Antipsychotics CNS	3Major	PD-additive + PK-CYP	curated B	Extrapyramidal symptoms, QT prolongation, excess sedation, or loss of ant…	why ▾
Class mechanism. Additive dopaminergic blockade, QT prolongation and sedation, plus CYP1A2, 2D6 and 3A4 modulation of clozapine, risperidone and quetiapine exposure. Expected Extrapyramidal symptoms, QT prolongation, excess sedation, or loss of antipsychotic control with inducers. Management ECG if other QT-prolonging agents are present. Consider clozapine level monitoring where inducers are stopped or started. Onset rapid Evidence B - reviewed clinical column, source pending Matched on “anti-psychotic” Find evidence for this pair Map this mechanism

05 Hazard register

The audit recorded no hazard beyond the interaction profile. The controlled-vocabulary field reads not assessed, which means the assessment has not been done rather than that it came back clear.

06 Confusable material

No same-genus or shared-common-name entry in the corpus.

07 Mechanism map

Chemistry sorts to the left, pharmacology to the right. Dashed edges are predicted. Drag nodes, scroll to zoom, export at 3× for a figure.

species

chemical class

marker compound

drug class

expected effect

hazard

08 Open literature

Abstract-scoped query built from this binomial, its common names and its marker compounds, run live against Europe PMC, PubMed and OpenAlex, then ranked locally against an evidence hierarchy.

Checking openFDA spontaneous reports…

09 Isomechanistic neighbours

Species whose interaction profile overlaps this one, ranked by shared severity weight rather than by count — a shared contraindication counts for more than a shared minor signal. Practical use: these are the plants you should not stack with this one, because the mechanisms summate.

Species	Family	Shared classes	Jaccard
Matricaria chamomilla Chamomile	Asteraceae	2	0.50
Serenoa repens Saw Palmetto	Arecaceae	2	0.50
Gaultheria fragrantissima Wintergreen	Ericaceae	2	0.50
Salix alba White Willow	Salicaceae	2	0.50
Filipendula ulmaria Meadowsweet	Rosaceae	2	0.50
Salvia miltiorrhiza Danshen	Lamiaceae	2	0.67

10 References and notes

No citation is on record for this entry. That is itself the finding: the audit flagged it, and it is why the entry does not carry an A evidence grade.

Curator notes

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