Does Evening Primrose oil cause weight gain?

Evening primrose oil isn’t likely to make you gain weight. On the contrary, it may help you lose weight.

Evening primrose oil (EPO) is a common ingredient in many weight loss supplements. Proponents of evening primrose claim it has numerous health benefits, and that taking EPO daily is beneficial for weight loss.

However there’s little scientific support for these claims. Studies of EPO for weight loss have not shown significant effects. On the other hand, there is no convincing scientific evidence that this oil can cause weight gain either.

People who sell weight loss supplements containing EPO, will often claim that it reduces bloating, suppresses appetite, and can balance your hormones. But is any of that true? 

Since these supplements can easily get expensive, before you spend your money, it is good to have a clear understanding of the basis for these claims.

1. Does evening primrose oil help you lose weight?

There is very little research done on this subject, but a number of relatively old studies did not find EPO to have any effect on body weight. One contemporary study claims it may be effective for formerly obese people.

• A double-blind trial from 1985 showed that EPO supplements did not have any effect on body weight (1). In addition to that a significant number of participants reported nausea and bloating during the treatment.

• An old animal study from 1988 conducted on dogs, found that even after long-term use of EPO for 52 weeks, there were no notable changes in either body weight or food intake, observed in the treated animals (2). It must be noted though, that the study was not investigating the effect of EPO on weight loss, but primarily its toxicity.

• Another study, that was primarily focussed on studying the effects of EPO on PMS symptoms, had similar results (3). After months of supplementation, they did not find any evidence that evening primrose is effective for either weight loss or fluid retention.

• A more recent double-blind trial claims that long-term use of GLA, one of the primary components of EPO, may reduce the regain of weight in formerly obese people (4).

2. Does evening primrose oil increase appetite?

Evening primrose oil is not likely to increase your appetite. In fact, many supporters of EPO supplements claim that it may help suppress appetite. However, at the moment, there is not enough scientific evidence to draw any conclusions.

• According to the animals study cited above, long-term use of EPO did not have any significant effects on food intake or body weight (5).

So it is likely that EPO neither increases nor suppresses your appetite.

3. Does EPO reduce bloating?

Bloating is often caused by factors such as overeating, gas production, digestive disorders, and food intolerances. 

While EPO is known for its many potential health benefits, there is nowhere near enough scientific evidence to support its effectiveness against bloating.

• In fact, the study from 1985 mentioned above, found that the EPO supplement they used, even caused bloating in some people (6).

If you come across a supplement claiming EPO supplements can reduce bloating, it would be wise to take this information with a grain of salt.

4. Does EPO reduce fluid retention?

Fluid retention, the abnormal accumulation of fluid in the body, occurs when there is an imbalance between the amount of fluid you take in, and the amount of fluid you excrete.

It can affect various parts of the body, and if you suffer from this, you know how puffy, bloated and uncomfortable it is. Getting rid of the excess fluid can help you lose a lot of weight in a short period of time and help you feel much better.

Fluid retention can have various underlying causes, including hormonal imbalances, kidney or liver problems, heart conditions, or certain medications. Treating it requires addressing the underlying cause. Relying on supplements for this is often not effective and could even be dangerous.

There is no scientific evidence that evening primrose oil is effective against fluid retention. 

• On the contrary, a study from 1990, found that EPO did not have any effect on the retention of fluids (7). 

• Although it must be said that the researchers focussed on women with PMS symptoms. They did not investigate the effects of EPO on other causes of fluid retention.

So if someone does make such claims, be aware that the evidence they are based on is probably quite dubious. Having said that, it is possible that EPO works for some people. 

5. Could evening primrose oil lower your cholesterol?

Many people who are trying to lose weight, have high cholesterol, which can be very damaging for your overall health in the long term. Studies suggest that EPO supplements could help increase the ‘good' HDL cholesterol, while lowering the levels of ‘bad' triglycerides (8).

In addition to that, the anti-inflammatory effects of this oil, can help protect against heart disease.  This is because chronic inflammation is a major risk factor for heart disease. 

• Studies show that some of the components in primrose oil, such as gamma linolenic acid, can help reduce inflammation markers in the body (9).

Side effects of Evening primrose oil

Not everyone reacts the same to primrose oil (source). Although it is generally safe for most people, it has some potential side effects. Uncommon side effects of EPO include:

• nausea

• feeling full

• symptoms related to indigestion

• headache

• upset digestive system

Some rare side effects include:

• inflammation

• allergic reactions

• rashes

• abdominal pain

• higher body temperature

Precautions

Seizures

Primrose oil could increase the incidence of seizures. People with epilepsy and schizophrenia should consult a doctor if they consider using it.

Increased bleeding

If you have a tendency to bleed easily or if you're currently taking anticoagulants or anti-platelet medications, it's crucial to consult with a healthcare professional before using EPO. This supplement has the potential to increase the risk of bleeding, so seeking medical advice is essential to ensure your safety.

My advice to you

The one thing I can tell you, is that when it comes to this kind of supplements, you should always proceed with caution. There are so many people taking this supplement for all kinds of reasons, but the truth is there is not enough research done on the subject.

Many people who take this supplement and claim it helped them one way or another, think that there is no scientific research because it is not profitable. I can not tell you, whether or not this is true.

There are many natural supplements that are not backed by science, but many people claim it helped them anyway. At the end of the day, you should decide for yourself whether or not something like this is worth trying.

Wrap up

• Currently there is not enough scientific evidence that EPO can help with weight loss. Despite this, numerous supplements sold on the market claim that it can suppress hunger and lead to weight loss.

• Even though there is not enough research to support the use of primrose oil against weight loss, there is not enough research to deny it either.

• Most research claims primrose oil does not have any effect on weight loss or weight gain (10).

• But we are all individuals and can react differently to the same supplement.

Dear readers, I did my best to find credible scientific evidence for this article. If there is anything I have overlooked, a study I have not noticed, or perhaps a more indirect connection that exists between primrose oil and weight loss, please let me know.