The short answer
Evening primrose oil has not been shown to increase nevirapine absorption, blood levels or adverse effects in an exact-pair human study. A laboratory constituent experiment is too indirect to establish those claims.
What this answer covers
Evening primrose oil from authenticated Oenothera preparations; isolated linoleic acid is not a finished botanical oil.
- Supplement or preparation
- Evening Primrose Oil
- Medication ingredient
- nevirapine
The laboratory lead is limited
An enzyme study tested purified compounds, including a fatty acid described as an evening-primrose-oil component. It did not administer a finished oil with nevirapine to people.
The relevant pathways are not fully represented
Nevirapine metabolism involves CYP3A and CYP2B6, with autoinduction. The laboratory panel did not include CYP2B6, and inhibition in an isolated enzyme system cannot establish the overall effect in a patient.
Blood levels and safety remain unmeasured
Neither increased absorption nor a clinical adverse-effect rate was established for this pair. Oil source, fatty-acid composition and other ingredients matter; absence of direct evidence is not proof of safety.
Review before co-use
Show the exact oil product to the HIV clinician and keep the prescribed monitoring plan. Do not change nevirapine dosing or rely on a timing gap to prevent an unconfirmed interaction.
Evidence and practical considerations
Absorption & effectiveness
Only indirect isolated-constituent CYP laboratory lead; no authenticated-oil/nevirapine human absorption, exposure or toxicity result. CYP2B6 omission and preparation boundaries preclude original Q2/Q3 validation.
- Exact scope
- Evening primrose oil from authenticated Oenothera preparations; isolated linoleic acid is not a finished botanical oil. with Nevirapine immediate-release oral tablets; extended-release formulation considered separately.
- Medication form and route
- oral medication; oral supplement
What remains uncertain
- No unmeasured pair incidence, blanket class transfer or arbitrary spacing interval.
Factors that may matter: Preparation; Dose; Other medicines; Organ function.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 11, 2026
Population: People prescribed nevirapine
Serious hepatic and skin reactions; metabolism through CYP3A and CYP2B6 with autoinduction. St John’s wort co-use not recommended because of reduced exposure/virologic risk.
How this applies: Exact nevirapine RxCUI 53654 IN, with stated salt/formulation/route bridge.
Exact route and formulation apply. Label precautions do not quantify untested botanical pairs or support arbitrary supplement doses.
Source 2: current product label
dailymed.nlm.nih.gov · Source check Sep 11, 2026
Population: People prescribed nevirapine
Shares CYP3A/CYP2B6 metabolism, autoinduction and serious liver/skin precautions. Different release/dosing formulation.
How this applies: Exact nevirapine RxCUI 53654 IN, with stated salt/formulation/route bridge.
Immediate-release and extended-release schedules are not interchangeable without the prescribed transition plan.
Source 3: Original laboratory enzyme study
pubmed.ncbi.nlm.nih.gov · Source check Sep 11, 2026
Population: Recombinant human CYP enzyme systems.
Some constituents inhibited CYP enzyme activity under laboratory conditions.
How this applies: Isolated constituent assay, not an authenticated finished oil, human nevirapine PK, absorption or safety study; CYP2B6 not among tested isoforms.
Isolated constituent assay, not an authenticated finished oil, human nevirapine PK, absorption or safety study; CYP2B6 not among tested isoforms.
Research assessment: · Open full citations ↗
Side effects & toxicity
Only indirect isolated-constituent CYP laboratory lead; no authenticated-oil/nevirapine human absorption, exposure or toxicity result. CYP2B6 omission and preparation boundaries preclude original Q2/Q3 validation.
- Exact scope
- Evening primrose oil from authenticated Oenothera preparations; isolated linoleic acid is not a finished botanical oil. with Nevirapine immediate-release oral tablets; extended-release formulation considered separately.
- Medication form and route
- oral medication; oral supplement
What remains uncertain
- No unmeasured pair incidence, blanket class transfer or arbitrary spacing interval.
Factors that may matter: Preparation; Dose; Other medicines; Organ function.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 11, 2026
Population: People prescribed nevirapine
Serious hepatic and skin reactions; metabolism through CYP3A and CYP2B6 with autoinduction. St John’s wort co-use not recommended because of reduced exposure/virologic risk.
How this applies: Exact nevirapine RxCUI 53654 IN, with stated salt/formulation/route bridge.
Exact route and formulation apply. Label precautions do not quantify untested botanical pairs or support arbitrary supplement doses.
Source 2: current product label
dailymed.nlm.nih.gov · Source check Sep 11, 2026
Population: People prescribed nevirapine
Shares CYP3A/CYP2B6 metabolism, autoinduction and serious liver/skin precautions. Different release/dosing formulation.
How this applies: Exact nevirapine RxCUI 53654 IN, with stated salt/formulation/route bridge.
Immediate-release and extended-release schedules are not interchangeable without the prescribed transition plan.
Source 3: Original laboratory enzyme study
pubmed.ncbi.nlm.nih.gov · Source check Sep 11, 2026
Population: Recombinant human CYP enzyme systems.
Some constituents inhibited CYP enzyme activity under laboratory conditions.
How this applies: Isolated constituent assay, not an authenticated finished oil, human nevirapine PK, absorption or safety study; CYP2B6 not among tested isoforms.
Isolated constituent assay, not an authenticated finished oil, human nevirapine PK, absorption or safety study; CYP2B6 not among tested isoforms.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Prepared exact nevirapine article with formulation-specific evidence and uncertainty. |
Article revision: 9b730eeff0365af0
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.