Report on Evening Primrose Oil Side Effects and Usage

Evening Primrose Oil

Natural health supplements sometimes have unexpected side effects or interactions with medication that can lead to adverse reactions that are sometimes life threatening. The following is a list of cautions that you should be aware of before using Evening Primrose Oil (Oenothera biennis). These are referred to as drug/herb interactions.

Warning 1 – Contraindications: This product is not recommended for use during pregnancy. Although Evening Primrose Oil passes into breast milk, it is unlikely to harm a nursing infant but check with your doctor first.

Warning 2 – Phenothiazines: The use of Evening Primrose Oil while taking phenothiazines may cause seizures. Examples of phenothiazines include:

  • chlorpromazine (brand name: Thorazine)
  • fluphenazine (Duraclon)
  • mesoridazine (Serentil)
  • perphenazine (Etrafon and Trilafon)
  • prochlorperazine (Compazine)
  • promazine (Robinul and Anectine)
  • thioridazine (Mellaril)
  • trifluoperazine (Stelazine)
  • triflupromazine (Robinul)

Warning 3 – Bleeding Disorders: Evening Primrose Oil may increase the chance of bruising and bleeding in those with bleeding disorders.

Warning 4 – Seizures: There is a concern that this product may increase the risk of seizures in those with a history of seizures.

Warning 5 – Surgery: Because of the chance of increased bleeding during or after surgery it is recommended to stop using Evening Primrose Oil 2 weeks before a scheduled surgery. This product is suspected to interact with anesthesia, which may increase the risk of seizure.

Warning 6 – Anticoagulants/Antiplatelets: Using Evening Primrose Oil may slow the clotting of blood, which increases the chances of bruising and bleeding. Check with your doctor before using Evening Primrose Oil if you take medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.

Warning 7 – Phentermine: Using Evening Primrose Oil with the diet drug Phentermine may increase the risk of seizures.

Used as a natural health remedy 1: Evening Primrose Oil is one of the safest sources of GLA, an essential fatty acid thought to have anti-inflammatory and other healing properties. This natural supplement is used internally (in capsules) for breast pain although it may not be effective for long-term severe breast pain.

Used as a natural health remedy 2: When combined with calcium and fish oil supplements Evening Primrose Oil is possibly effective for osteoporosis.

Evening Primrose Oil can help with the symptoms of menopause; fatigue, joint pain, alopecia (hair loss) and dry skin.

Used as a natural health remedy 3: Evening Primrose Oil is also used to relieve the symptoms of hyperlipidemia (excess lipids in the blood), atopic eczema, and psoriasis.

Although Evening Primrose Oil is used for the following conditions and diseases, there is not enough evidence to support its effectiveness.

  • Acne
  • Alcoholism
  • Alzheimer’s disease
  • Asthma
  • Cancer
  • Chronic fatigue syndrome (CFS)
  • Dyspraxia (movement disorder in children)
  • Heart disease
  • High cholesterol
  • Hyperactivity in children and attention deficit-hyperactivity disorders (ADHD)
  • IBS (irritable bowel syndrome)
  • Insomnia
  • Intermittent claudication (leg pain due to blocked blood vessels)
  • Low libido
  • Multiple Sclerosis (MS)
  • Neurodermatitis (Nerve damage related to diabetes; an itching disorder)
  • Obesity and weight loss
  • Osteoporosis (weak bones)
  • Peptic ulcer disease
  • Raynaud’s syndrome
  • Rheumatoid arthritis (See other herbs for inflammation)
  • Schizophrenia
  • Sjogren’s syndrome
  • Ulcerative colitis
  • Whooping cough

Evening Primrose Oil Side Effects

This supplement is generally considered to be safe but it may also cause mild side effects including:

  1. gastrointestinal upset
  2. headache
  3. nausea
  4. diarrhea

If any of these side effects persist or worsen contact your doctor. Other side effects may also occur when using Evening Primrose Oil. (See form below)

As with any herb, a serious allergic reaction is possible. Seek immediate medical attention if you notice any symptoms of a serious allergic reaction. These may include a rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, or trouble breathing.

Return to the Herb List.

For questions and answers about the side effects of herbs see the Herb Forum

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