Evening Primrose Ingredients & Drug Interactions
by Herbal Terra
What is this page for?
First and foremost: checking Evening Primrose against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.
Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy
Evening Primrose is a dietary supplement by Herbal Terra with 1 active ingredient. Its ingredients are commonly taken for eczema and skin health, pms symptoms, breast pain (mastalgia).Based on those ingredients, 233 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are certified organic Evening Primrose (Oenthera biennis) flower liquid extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Evening Primrose by Herbal Terra
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AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of Evening Primrose by Herbal Terra
Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.
What’s inside
Full disclosure
This product contains one active ingredient: certified organic Evening Primrose flower liquid extract. Evening primrose oil is the compound most studied from this plant; it contains gamma linolenic acid (GLA) and linoleic acid, which are the components responsible for its effects on blood clotting and drug interactions.
The liquid also contains menstruum (a liquid used to extract the plant material) as an inactive ingredient.
Does it work?
Couldn't assess
The evidence for evening primrose is mixed and limited. It's rated likely ineffective for breast pain (mastalgia) and possibly ineffective for asthma.
For acne, attention deficit-hyperactivity disorder (ADHD), abortion induction, and hysteroscopy, we don't have enough reliable evidence to know whether it works. If you're considering this product for a specific condition, talk to your pharmacist or doctor about what the current evidence actually supports.
How safe is it?
Well-documented data
Evening primrose oil is generally well tolerated when taken by mouth in the short term, though quality evidence and long-term safety data are limited. The most common side effects reported are gastrointestinal — abdominal pain, diarrhea, indigestion, gas, nausea, and vomiting.
Less common reports include skin rash, acne, dizziness, and headache. During pregnancy and breastfeeding, safety data is incomplete; the product is rated possibly safe, but evidence is unclear enough that you should talk with your doctor before using it if you're pregnant or nursing.
Meds to double-check
Moderate interaction found
Before taking Herbal Terra Evening Primrose, double-check with your pharmacist if you take blood thinners (anticoagulants) or antiplatelet drugs — moderate interaction risk. Also flag lithium, phenothiazines (antipsychotics), lopinavir/ritonavir (an HIV medication), and CYP2C9 substrate drugs — all have documented interactions with evening primrose oil.
The bottom line
Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.
Evening primrose might appeal to someone interested in plant-based approaches, but the evidence for what it actually does is weak to absent. More importantly, if you take blood thinners, lithium, antipsychotics, HIV medications, or certain other drugs, you need to check your specific prescriptions with your pharmacist before starting this — it could affect how your medications work.
Talk to your pharmacist about whether this product fits your situation.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Sep 25, 2020.
This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed
General information
Key facts about Evening Primrose, straight from the product label.
| Brand | Herbal Terra |
|---|---|
| Barcode (UPC) | 0617503381408 |
| Net contents | 4 Fluid Ounce(s); 120 mL |
| Market status | On market |
| Date entered into DSLD | Sep 25, 2020 |
| DSLD ID | 234844 |
| Product type | Botanical |
| Supplement form | Liquid |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Adult (18 - 50 Years), Organic, Gluten Free |
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.
Supplement Facts
The label details for Evening Primrose by Herbal Terra, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| certified organic Evening Primrose (Oenthera biennis) flower liquid extract | 970 mg | -- |
Other ingredients: Menstruum
Tap any ingredient to jump to its full detail below.
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions
Direction Shake well before use. Adults take up to 30 drops (1 mL, one full squeeze of the dropper bulb) in 3-4 fl. oz of juice or water up to 4 times a day. We recommend to seek expert medical advice before taking this or any other herbal supplements.
FDA Disclaimer Statement
Notice This product has not been evaluated by the FDA and is not intended to diagnose, treat, cure, or prevent any disease.
Formulation
Manufactured in the USA in an FDA registered facility
Alcohol free
Dried herb/menstruum ratio: 1:3 Expertly extracted Laboratory tested 330 mg/1 mL Premium product Alcohol-free liquid herbal extract
Non GMO
No artificial ingredients, GMO, gluten, color additives, fillers, preservatives or binders. Natural Gluten Free
Precautions
Caution May have contraindications.
Do not use if you are allergic to any ingredients.
Consult a physician before using during pregnancy, if nursing, or if you are on any medications.
Keep out of the reach of children.
Storage
Store in a cool, dry, dark place.
Formula
Oenothera biennis
FDA Statement of Identity
Herbal Supplement
Seals/Symbols
Made in USA Made in an FDA registered facility Natural Gluten Free
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Evening Primrose by Herbal Terra label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.
View the full label (PDF)The Ingredients in Evening Primrose by Herbal Terra
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 mL Dosage formLiquid Servings per container120 Amounts shown are per serving.
Certified organic Evening Primrose (Oenthera biennis) flower liquid extract
Interacts with233 drugs
Evening primrose oil is a seed oil rich in gamma-linolenic acid (GLA), an omega-6 fatty acid, that is popularly used for skin conditions, PMS, and bre...
Certified organic Evening Primrose (Oenthera biennis) flower liquid extract monograph & interactionsOther (inactive) ingredients: Menstruum. These complete the product’s ingredient list but are not active constituents.
Evening Primrose by Herbal Terra Drug Interactions
HelloPharmacist Interaction Report
Herbal Terra Evening Primrose is a single-ingredient liquid extract that does interact with several medication types.
The most serious concern is with blood thinners (anticoagulants) and antiplatelet drugs — evening primrose oil may increase bleeding risk because one of its components can reduce how your blood clots and prolong bleeding time.
Read the full breakdown — every affected drug type, severity by severity
Moderate interactions also affect lithium (a mood stabilizer), where evening primrose may lower lithium levels and reduce how well it works — a case report showed lithium levels dropped significantly after someone started evening primrose oil. Phenothiazines (antipsychotic medications) carry a moderate risk too; there's concern that evening primrose oil might lower your seizure threshold when combined with these drugs.
Additionally, if you take lopinavir/ritonavir (an HIV medication), evening primrose may raise its levels in your blood.
There's a minor interaction with a group of drugs called CYP2C9 substrates — evening primrose oil may increase their levels and effects.
Altogether, these interactions span 230 individual medications. Before you start this product, use the medication checker on this page to look up your exact prescriptions.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Evening Primrose?
Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.
Go to the checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Evening Primrose interact with 233 drugs. Click any drug to see the details.
1 of the 1 ingredient in Evening Primrose interact with drugs. Each result below shows which ingredient is responsible. certified organic Evening Primrose (Oenthera biennis) flower liquid extract
DanaparoidOrgaran
How Danaparoid interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Danaparoid interactionDarunavir, RitonavirDarunavir, Ritonavir
How Darunavir, Ritonavir interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractLopinavir/ritonavir (kaletra) Moderate
Interaction Summary
Theoretically, evening primrose oil might increase the levels and effects of lopinavir.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Darunavir, Ritonavir interactionDasabuvir Sodium, Ombitasvir, Paritaprevir, RitonavirViekira XR
How Dasabuvir Sodium, Ombitasvir, Paritaprevir, Ritonavir interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractLopinavir/ritonavir (kaletra) Moderate
Interaction Summary
Theoretically, evening primrose oil might increase the levels and effects of lopinavir.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Dasabuvir Sodium, Ombitasvir, Paritaprevir, Ritonavir interactionDefibrotide SodiumDefitelio
How Defibrotide Sodium interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Defibrotide Sodium interactionDiclofenacZorvolex
How Diclofenac interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Diclofenac interactionDiclofenac PotassiumCambia, Cataflam, Cataflam IR, Voltaren Rapide, Voltarol Rapid
How Diclofenac Potassium interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Diclofenac Potassium interactionDiclofenac SodiumAcoflam, Acoflam 75 SR, Acoflam Retard, Defenac, Defenac Retard, Defenac SR +40 more
How Diclofenac Sodium interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Diclofenac Sodium interactionDiclofenac Sodium, MisoprostolArthrotec 50, Arthrotec 75
How Diclofenac Sodium, Misoprostol interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Diclofenac Sodium, Misoprostol interactionDiclofenac EpolamineFlector, Licart
How Diclofenac Epolamine interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Diclofenac Epolamine interactionDicumarolDicumarol
How Dicumarol interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Dicumarol interactionDiphenhydramine Hydrochloride, Naproxen SodiumAleve PM
How Diphenhydramine Hydrochloride, Naproxen Sodium interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Diphenhydramine Hydrochloride, Naproxen Sodium interactionDipyridamoleDipyridamole, Persantin, Persantin Injection, Persantin Retard, Persantine
How Dipyridamole interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Dipyridamole interactionEdoxabanSavaysa
How Edoxaban interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Edoxaban interactionEffientPrasugrel
How Effient interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Effient interactionEnoxaparinLovenox
How Enoxaparin interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Enoxaparin interactionEptifibatideIntegrilin
How Eptifibatide interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Eptifibatide interactionEsomeprazole, NaproxenVimovo
How Esomeprazole, Naproxen interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Esomeprazole, Naproxen interactionFamotidine, IbuprofenDuexis
How Famotidine, Ibuprofen interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Famotidine, Ibuprofen interactionFish Oil TriglyceridesOmegaven
How Fish Oil Triglycerides interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Fish Oil Triglycerides interactionFluphenazineFluphenazine, Permitil, Prolixin
How Fluphenazine interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractPhenothiazines Moderate
Interaction Summary
Theoretically, taking evening primrose oil with phenothiazines might increase the risk of convulsions.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Fluphenazine interactionFondaparinuxArixtra
How Fondaparinux interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Fondaparinux interactionHeparinHeparin
How Heparin interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Heparin interactionHydrocodone, IbuprofenVicoprofen
How Hydrocodone, Ibuprofen interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Hydrocodone, Ibuprofen interactionIbrutinibImbruvica
How Ibrutinib interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Ibrutinib interactionIbuprofenAdvil, Arthrofen, Brufen, Brufen Retard, Calodor, Calprofen +14 more
How Ibuprofen interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Ibuprofen interactionIbuprofen LysineNeoProfen
How Ibuprofen Lysine interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Ibuprofen Lysine interactionIbuprofen, AcetaminophenAdvil Dual Action
How Ibuprofen, Acetaminophen interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Ibuprofen, Acetaminophen interactionIbuprofen, HydrocodoneIbucodone
How Ibuprofen, Hydrocodone interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Ibuprofen, Hydrocodone interactionIbuprofen, OxycodoneCombunox
How Ibuprofen, Oxycodone interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Ibuprofen, Oxycodone interactionIbuprofen, PseudoephedrineDristan
How Ibuprofen, Pseudoephedrine interacts with Evening Primrose — through 1 ingredient. Tap an ingredient for the detail:
Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid ExtractCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Certified Organic Evening Primrose (oenthera Biennis) Flower Liquid Extract + Ibuprofen, Pseudoephedrine interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Evening Primrose with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.
certified organic Evening Primrose (Oenthera biennis) flower liquid extract
Anticoagulant/Antiplatelet Drugs
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Evening primrose oil contains gamma linolenic acid (GLA). There is preliminary clinical evidence that GLA can reduce platelet aggregation and prolong bleeding time.
Lithium
Theoretically, concomitant use of lithium with evening primrose oil might decrease lithium levels and effects.
In a case report, a patient on a stable dose of lithium for 10 years experienced a reduction in lithium levels after taking evening primrose oil 500 mg daily. Baseline levels were 0.69 mmol/L, which decreased to 0.37 mmol/L after 2 months and 0.23 mmol/L after 3 months of use. Lithium levels increased within 6 weeks of discontinuing evening primrose oil, to 0.73 mmol/L; no clinical effects were noted.
Lopinavir/Ritonavir (Kaletra)
Theoretically, evening primrose oil might increase the levels and effects of lopinavir.
In a case report, an HIV patient who took evening primrose oil (Efamol) along with lopinavir/ritonavir experienced an increase in serum levels of lopinavir to 15.2 mg/L. Six weeks after discontinuing evening primrose oil, levels of lopinavir returned to the normal range of 5-10 mg/L. When re-challenged with evening primrose oil for a week, the patient's lopinavir levels increased from 6.69 to 8.11 mg/L. It is suspected that evening primrose oil increases levels of lopinavir by inhibiting cytochrome P450 3A4 (CYP3A4), which metabolizes lopinavir. However, this effect has not been reported in other research.
Phenothiazines
Theoretically, taking evening primrose oil with phenothiazines might increase the risk of convulsions.
Evening primrose oil contains gamma-linolenic acid (GLA). There is some concern that taking supplements containing GLA might cause seizures, or lower the seizure threshold, when taken with phenothiazines. In one report, three patients with schizophrenia who had received phenothiazines developed EEG changes suggestive of temporal lobe epilepsy after starting treatment with GLA, although none experienced an actual seizure. In another report, two patients with schizophrenia who were stabilized on phenothiazines developed seizures when evening primrose oil 4 grams daily was added. One of these patients had a prior history of seizures. It is unclear whether evening primrose oil had any additive epileptogenic effects with the phenothiazines; there is no evidence that taking evening primrose oil alone causes seizures.
Cytochrome P450 2C9 (Cyp2C9) Substrates
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
In vitro research shows that linoleic acid, a constituent of evening primrose oil, inhibits CYP2C9.
Brand information
Manufacturer and brand details for Evening Primrose, from the product label.
Evening Primrose by Herbal Terra: Common Questions
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Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Evening Primrose is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.
The Full Monographs Behind Evening Primrose’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Sources & How We Checked
Evening Primrose's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.
The 33 references behind this product’s interaction data
Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.
Evening Primrose 33 references
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