Evening primrose oil: Benefits, dosage, side effects, uses & more

What is evening primrose oil?

Evening primrose oil comes from the seeds of the yellow wildflower, Oenothera biennis. It's naturally rich in linoleic acid and gamma-linolenic acid (GLA), both essential omega-6 fatty acids. GLA, in particular, helps the body form substances called prostaglandins, which play a role in soothing inflammation.

Many people, especially women, use evening primrose oil (EPO) to ease symptoms tied to PMS and menopause, including hot flushes. It's also taken for skin conditions like eczema and acne. Most often, it's available in capsule form but can occasionally be found as a liquid.

10 benefits of evening primrose oil

Historically, Indigenous American communities used various parts of the evening primrose plant to treat digestive and liver issues. Today, its oil is often used as a herbal remedy for managing itchy, dry skin and other health concerns.

1. Menopause symptoms

There’s a wealth of anecdotal feedback suggesting that EPO helps manage menopause symptoms, particularly hot flushes. A 2013 study found that taking it over six weeks reduced the frequency, severity, and duration of hot flushes. Many of the women in the study also felt a noticeable boost in overall wellbeing.

2. Pre-menstrual syndrome (PMS)

EPO is commonly used to reduce symptoms like bloating, breast tenderness, and mood changes during PMS. The Royal College of Obstetricians and Gynaecologists has noted its potential to ease breast discomfort. A 1983 study even described EPO as “highly effective” for PMS, though more research is needed to confirm these results.

3. Dry skin conditions

The European Medicines Agency approves the short- and long-term use of EPO for relieving itching in dry skin conditions. It's often used by people with eczema to help manage dryness and itchiness, although a 2013 Cochrane Review found it no more beneficial than a placebo when it came to treating eczema specifically.

4. Acne

GLA in EPO may help reduce inflammation linked to acne and may even lessen scarring. A Korean study from 2014 found promising results, with reduced inflammation in acne sufferers. Still, more robust evidence is needed before it's widely recommended for acne treatment.

5. Arthritis

Some people with rheumatoid arthritis take EPO to ease joint pain and stiffness. One study noted less morning stiffness in patients using the oil. While the overall evidence is not definitive, some groups, including Versus Arthritis, believe it may help regulate pain and inflammation.

6. Osteoporosis

Higher unsaturated fat intake is linked with reduced bone loss in postmenopausal women. Given that EPO is nearly all unsaturated fat, it's thought to support bone health, especially in women with osteoporosis or older adults at risk of bone density loss.

7. Bile flow

Initial research suggests that taking 2g of EPO twice daily for 12 weeks may improve itching related to liver conditions that reduce bile flow. Some people start to notice improvements within one to two weeks of starting treatment.

8. Chronic Fatigue Syndrome (CFS)

One early study proposed that combining EPO with fish oil could ease post-viral CFS-like symptoms. However, another study found no significant benefit for people formally diagnosed with CFS when using the same combination product.

9. Dry eyes

Preliminary findings show that taking 3g of a specific EPO product daily for six months helped reduce dry eye symptoms in female contact lens users.

10. Cholesterol levels

Some studies have pointed to EPO’s ability to lower total cholesterol and triglycerides, while boosting HDL (good) cholesterol. Yet other research shows conflicting outcomes, indicating more studies are needed.

Dosage

For adults, a common dose ranges from 500mg to 1,300mg of evening primrose oil per day. It’s important not to give it to children unless recommended by a healthcare provider. The European Medicines Agency advises against its use in children under 12.

When to take evening primrose supplements

There’s no strict rule about taking EPO in the morning or at night. It’s best to follow label instructions, and take one to three capsules daily with a meal for better absorption. Choose a time that fits your schedule and is easy to remember.

Evening primrose side-effects

Most side effects are mild and may include:

  • Nausea
  • Diarrhoea
  • Indigestion
  • Headaches
  • Rare allergic reactions – such as rash, itching, or trouble breathing. Seek urgent medical help if symptoms occur.

Potentially more serious effects include:

  • Increased bleeding risk – especially when combined with blood-thinning medications
  • Heightened seizure risk – for individuals on phenothiazines used to manage psychotic disorders
  • Lowered blood pressure – which may affect those on antihypertensive medications
  • Seizures – in rare cases when combined with anesthesia

Disclaimer

The advice in this article is for informational purposes only and is not a substitute for medical care. Always consult your GP or healthcare provider before using supplements, treatments, or remedies. Supplements should not replace a balanced diet and healthy lifestyle.

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