The Ultimate List of Benefits of Evening Primrose Oil

(Last Updated On: August 3, 2018)

So many claims are made about the health benefits of taking evening primrose oil, yet only a small number of the claims have good scientific support, and since it’s important to take the right natural remedies and preventive measures, we’re going to look at some of the most common claims and find out if they pass the reality test.

What Is Evening Primrose Oil?

Evening primrose oil is extracted from the seeds of the evening primrose flower, a pretty, yellow wildflower native to North America and which grows throughout the US. The plant gets its name because the flowers don’t bloom until sunset.

Native Americans made good use of the plant, using the seeds as a food, and crushing the flowers and stems to make a poultice used to speed the healing of bruises and soothe hemorrhoids.

Using the oil contained in the seeds for medicinal purposes is a relatively recent development and the oil is considered useful because of its GLA component. Evening primrose oil supplements are standardized to 8% GLA and 72% linolenic acid.

Evening Primrose Oil and GLA

GLA, or to give it its full name, Gamma-linolenic acid, is an omega-6 essential fatty acid. Our bodies can’t make GLA so we have to obtain it from food.

The majority of people get their GLA by way of linolenic acid which is a very common omega-6 fatty acid found in vegetable oils. In the body, metabolic enzymes convert linolenic acid to GLA.

However, prior to conversion to GLA, linolenic acid is a pro-inflammatory which means that it causes damage to the body. More damage than the smaller amount of resulting GLA can rectify.

It’s a good idea to reduce (but not completely eliminate)  the amount of omega-6 fatty acids in your diet and increase your intake of beneficial omega-3 fatty acids.

Restoring the proper balance between omega-6 and omega-3 fatty acids often goes a long way to improving many of the conditions that people attempt to relieve by taking evening primrose oil and other anti-inflammatory supplements.

The ratio of omega-6 to omega-3 fatty acids should be in the region of 1:1 to 4:1, however most Americans have a ratio that is somewhere between 11:1 and 30:1.

This imbalance has serious implications for good health and increases the likelihood of heart disease, cancer, asthma, arthritis and depression.

Other sources of GLA besides evening primrose oil include borage oil  (best source with 24% GLA), black currant seed oil, hemp seed oil  and spirulina.

What Does GLA Do?

Your body breaks GLA down into dihomo gamma-linolenic acid (DGLA) and arachidonic acid (AA).

DGLA is beneficial and fights inflammation in the body, while AA is another pro-inflammatory substance. The presence of DGLA is able to negate the harmful effects of AA, however the amount of DGLA that your body produces from GLA is dependant on the presence of certain other nutrients.

If you’re low on magnesium, zinc, vitamin B6, vitamin B3 or vitamin C –  and many people are – then your body will make more of the damaging AA.

So basically, GLA is an essential fatty acid that once broken down into DGLA acts as a powerful anti-inflammatory in your body.

It’s important to remember that you don’t need huge amounts of GLA, and that many other foods (and supplements) also have potent anti-inflammatory effects. And if you aren’t actively contributing to inflammation in your body, then you’ll have less of it to deal with.

Following a healthy diet, getting some exercise,  losing weight if you need to, and sleeping well are all ways to minimize the inflammation in your body.

Okay, now we’ve established that evening primrose oil is a good source of healthy GLA, let’s find out how evening primrose oil and other sources of GLA can help you.


Their is no one cause of ADHD and therefore no simple solution, however careful control of children’s diets and correcting nutritional deficiencies often brings vast improvements.

Clinical studies have found that children with attention deficit and hyperactivity disorder tend to have low levels of essential fatty acids – both omega 6 and omega 3 – which are essential to normal brain function.

Some studies have demonstrated improvements when children are given omega-3 supplements but as yet no benefit has been demonstrated with evening primrose oil or GLA.

If you’re a parent of a child with ADHD, you might want to try evening primrose oil or borage oil and see if anything changes. You could also ask ADHD support groups for their opinion on the matter as they may have a body of anecdotal evidence to draw from.


Evening primrose oil and GLA have been used to reduce the severity of allergies

Evening primrose oil and GLA have been used to reduce the severity of allergies but there is as yet no scientific support for their use and more research needs to be carried out in this area.

Research has however shown that women who suffer from allergies have lower levels of GLA in their blood and in their breast milk.

Breast Cancer

Findings on GLA supplements and breast cancer are mixed.

One study found that women taking the breast cancer drug Tamoxifen had a better response to the drug when they supplemented with GLA.

Other research shows that GLA can inhibit tumor activity in breast cancer cell lines.

However, some research suggests that a diet rich in omega-6 oils promotes breast cancer development, so if you have been diagnosed with breast cancer, you must consult your doctor before supplementing with evening primrose oil or other sources of GLA.

Diabetic Nerve Pain (Neuropathy)

Diabetic neuropathy is difficult to treat and clinicians often resort to prescribing antidepressants as a treatment for this type of chronic pain. But when conventional treatments fail to control the pain, sufferers look elsewhere for relief, and one source of relief may be evening primrose oil.

One small trial found that patients taking evening primrose oil for 6 – 12 months experienced statistically significant improvements over those taking a placebo. Improvements were seen in overall neuropathy scores as well as in nerve conduction tests.

Results from GLA and evening primrose supplements may be better for those who have good blood sugar control.

Eczema Relief

Sufferers of eczema may find relief from the worst of their symptoms if they use evening primrose oil.

Currently more than 30 studies have attempted to demonstrate evening primrose oil’s beneficial effects on eczema, including one study of 1,207 people which reported that the supplement helped relieve itchy skin, crusting, redness and swelling. It should be noted that trials demonstrating the benefits of evening primrose oil were sponsored by the supplement manufactures.

Research also found high concentrations of linolenic acid (remember that’s a pro-inflammatory fatty acid) in the blood, milk and fatty tissue of patients with atopic eczema, but the presence of the beneficial metabolites of linolenic acid (GLA and DGLA) were greatly reduced.

Critics of these studies have pointed out flaws in their methodology and in 2002 after a review of the scientific literature on evening primrose oil, the UK’s Medicines Control Agency withdrew marketing authorizations for evening primrose oil as a prescription eczema treatment.

Where does this leave you if you suffer from eczema? If you want to try evening primrose oil, you’ve got nothing to lose if it doesn’t work apart from a few dollars, you may even find that it does improve your eczema.

Supporters of the use of evening primrose oil point out that you need to use the oil for several weeks before you can expect to see any benefits.

Healthy Aging

As we age our bodies produce less of the enzyme needed to convert linolenic acid into GLA, so to maintain adequate levels of this potent anti-inflammatory it’s a good idea to supplement with evening primrose oil or another form of GLA as well as to ensure a good intake of the nutrients needed to enable GLA to transform into DGLA rather than AA.

High Blood Pressure

There’s some promising research that shows the beneficial effects of GLA on high blood pressure (hypertension).

Research has found that GLA may have the ability to reduce high blood pressure when taken alone or in combination with omega-3 fish oils containing both EPA and DHA.

Another study, in men with borderline high blood pressure found that those who took blackcurrant oil (a source of GLA) experienced a reduction in diastolic blood pressure compared to those taking  a placebo.

GLA combined with EPA (from fish oil) lowered systolic blood pressure in patients suffering from pain in the legs caused by intermittent claudication – a condition caused by blockages in the blood vessels.

Before you supplement with evening primrose or any other source of GLA, you must talk to your doctor because GLA can interfere with blood thinning medications.

Menopausal Symptoms

Many women take evening primrose to help combat menopausal symptoms. Research hasn’t proven one way or another if evening primrose oil can deliver benefits beyond the placebo effect, although one study has demonstrated that evening primrose oil has some effect on reducing hot flashes.

Women in the study took either 2 x 500mg capsules of evening primrose oil or a placebo for 6 weeks. At the end of that period, researchers measured the severity of hot flashes experienced by the two groups. Improvements in the frequency, severity and duration for the evening primrose groups were 39, 42 and 19%, while in the placebo group the improvements were 32, 32 and 18%

If you’re suffering with menopausal symptoms, it may be worth trying evening primrose oil or another source of GLA for a while to see if it can bring you some relief.


Evening primrose oil and GLA aren’t a magic bullet that will effortlessly melt excess pounds

There are a lot factors involved in obesity, it isn’t just a matter of shoveling more food into your mouth than your body needs for energy. Nutritional deficiencies play a part, messed up hormones matter, stress gets a look in and so do the types of bacteria inhabiting your gut.

Evening primrose oil and GLA aren’t a magic bullet that will effortlessly melt excess pounds away but research has discovered that a defect in the enzyme responsible for converting dietary fatty acids into GLA may make people more likely to develop insulin resistance which is well known to be a root cause of obesity and of type 2 diabetes.

Supplementing with evening primrose oil or other sources of GLA may be of help to those with a lot of weight to lose if poor GLA production is a factor in their weight gain.


One study in women over 65 found that those taking GLA combined with EPA (fish oil) had less bone loss over a three year period than those study participants taking placebo.

In addition to experiencing less bone loss, many of the women taking the supplements actually saw increased bone density.

Another very important nutrient for good bone health is magnesium, and the Journal of the American Geriatrics Society reported on a study showing that for women in early menopause, increasing magnesium intake by 250 – 750 mg per day for one year resulted in higher bone density for 71% of women. Bone density usually reduces by 3 – 8% during that time.

Pre Menstrual Syndrome

Scientific support is once again lacking for this claim, but many women find relief from their symptoms by regularly taking evening primrose oil.

The only element of PMS that appears to marginally respond to evening primrose oil is breast tenderness (mastalgia), and for that symptom, evening primrose oil needs to be taken with vitamin E.

It was thought for a time that evening primrose oil should be a logical treatment for PMS as the condition is often related to excess amounts of the hormone prolactin.

A substance called Prostaglandin E1 (PGE 1) is known to reduce the effects of prolactin, and researchers supposed that PMS could be due to women having low levels of PGE 1 in their system. Their solution was to increase levels of PGE 1 via supplementation with GLA, as PGE 1 is one of its metabolites.

So far so good, except the clinical trials were a wash out and GLA supplementation produced no benefit over and above placebo (dummy pills).

If you suffer from PMS, you might like to try the supplement anyway, even if any benefits can be attributed to the placebo effect. After all relief is relief, even if it comes from your own mind and not the active constituents of a supplement or medication.

The placebo effect is not well understood but it is nevertheless very real, and it still works when people are aware that they are taking a placebo.

Rheumatoid Arthritis

As mentioned earlier, the GLA in evening primrose oil metabolizes first to DGLA and then further to a prostaglandin called PGE 1. PGE 1 is a powerful but short lived anti-inflammatory, and it’s this component of evening primrose oil and other sources of GLA that can deliver much needed relief from the pain of rheumatoid arthritis.

Some research has shown that early morning stiffness, pain and swelling all respond well to GLA, although it does take up to 3 months for benefits to show.

Who Shouldn’t Take Evening Primrose Oil?

While evening primrose oil is sold as an over-the-counter supplement it isn’t safe for everyone to take.

Those who should avoid evening primrose oil and other GLA supplements include:

  • Pregnant women – GLA can harm the fetus and induce early labor.
  • Men at risk of, or suffering from, prostate cancer.
  • Those with seizure disorders.
  • Those on blood thinners.
  • Those on some psychiatric medications like Thorazine and Compazine.

Doses greater than 3,000mg of GLA per day should be avoided because at that level they can become pro-inflammatory instead of anti-inflammatory.

Side effects may include headache, abdominal pain, diarrhea and nausea..

Wrapping It All Up

Evening primrose oil was a big deal in the 80’s and early 90’s when there were far fewer nutritional supplements around.

Many studies have since looked into evening primrose oil and some have found it to beneficial for certain conditions while others researching the same conditions have found it to be useless or no more effective than a placebo.

Several conditions do respond positively to evening primrose oil and other forms of GLA. these are diabetic neuropathy, rheumatoid arthritis, osteoporosis and some forms of high blood pressure.

Evening primrose oil contains 8% GLA which is an anti-inflammatory essential fatty acid, but the rest of the oil is made up from linolenic acid which is a pro-inflammatory fatty acid. Both are types of omega-6 fatty acids.

Supplementing with omega 6-fatty acids if you already have a very high ratio of omega-6 fatty acids in your diet compared to omega-3’s isn’t considered a smart health move.

Far more research exists demonstrating the beneficial anti-inflammatory effects of omega-3 fatty acids than it does for omega-6 fatty acids.

The GLA contained in evening primrose oil is an essential nutrient, but your body synthesizes GLA from the linolenic acid found in commonly used vegetable oils, so you’re unlikely to be deficient. The exception is in more elderly people who have lower levels of the converting enzyme present.

Evening primrose oil is generally safe for most people and is relatively inexpensive. If you decide to try it, it won’t do you any harm, but outside of a few specific conditions, it’s also unlikely to do you much good, and has in fact been described by the British Medical Journal as “the remedy for which there was no disease.”

If you do plan on trying evening primrose oil, make sure that you buy a good quality supplement from a reputable manufacturer, as an oil that has been allowed to oxidize will have zero benefits.

Written by Irina Radosevic MD
Irina graduated from the University of Belgrade, School of Medicine as a Doctor of Medicine (MD) and spent over 3 years working in the Clinical Hospital Center Zvezdara, in the Department of Emergency Medicine. She also undertook a postgraduate in Cardiology from the same University and had previously worked for over a year as a Physician and Nutritionist Dietitian for the Fitness club Green Zone. She eventually left her chaotic but fulfilling job in the ER to pursue her passion of writing, travelling and mountain climbing which has included writing a first aid course for the alpine club of Belgrade. Irina currently works as a VA for PintMedia focusing on medical and travel writing. Feel free to connect with Irina on LinkedIn and FaceBook. Her CV can be seen here.