Evening primrose oil (EPO) has numerous possible health benefits, such as treating acne. However, more research is necessary.

Evening primrose oil (EPO) is made from the seeds of evening primrose flowers, native to North America.

EPO’s healing benefits may be due to its gamma-linolenic acid (GLA) content. GLA is an omega-6 fatty acid found in plant oils.

EPO is available as a supplement or topical product.

Read on to learn more about the possible health benefits of EPO, the possible side effects, and more.

EPO may have some potential benefits.

However, more research is still necessary. The National Center for Complementary and Integrative Health (NCCIH) states that there isn’t enough evidence to support the use of EPO for any health conditions.

EPO is generally safe for adults to use, and some studies have highlighted areas of possible benefit.

Ease acne

Some people believe the GLA in EPO may help acne by reducing skin inflammation and the number of skin cells that cause lesions. It may also help the skin retain moisture.

According to a 2022 study, EPO may help relieve specific side effects from the medication isotretinoin (Accutane).

Manage eczema

Some research suggests that EPO could help manage symptoms of eczema.

A 2018 study in South Korea concluded that EPO improved the Eczema Area Severity Index (EASI) score in people with mild eczema compared to a placebo.

The authors of the study noted that transepidermal water loss and skin hydration were slightly improved in the EPO group.

The review didn’t look at the effectiveness of topical EPO for eczema.

Improve overall skin health

The GLA in EPO may benefit skin structure and function. As the skin can’t produce GLA alone, taking GLA-rich EPO may help keep the skin healthy.

Both previously mentioned studies noted that EPO improved skin hydration in participants.

Relieve PMS symptoms

A 2019 study suggests EPO may be effective in treating premenstrual syndrome (PMS) symptoms, such as:

  • breast swelling
  • irritability
  • bloating
  • acne

Researchers believe some people experience PMS because they’re sensitive to prolactin levels in the body. GLA converts to a substance in the body (prostaglandin E1) thought to help prevent prolactin from triggering PMS.

Minimize breast pain

Some people may use EPO to relieve cyclical breast pain.

Some people believe the GLA in EPO is thought to reduce inflammation and help inhibit prostaglandins that cause cyclical breast pain.

However, a 2021 review of research found that EPO was only as effective as a placebo compared with topical nonsteroidal anti-inflammatory drugs (NSAIDs), danazol, and vitamin E.

The authors also noted that EPO is unlikely to cause adverse side effects, so it may be safe to try.

Reduce hot flashes

Some people believe EPO may reduce the severity of hot flashes, which can happen with menopause.

A small 2021 study that used participant questionnaires found that taking EPO during menopause may result in less frequent and less severe night sweats.

However, more research is necessary to support this.

Improve heart health

Some people are using natural remedies, such as EPO, to help improve heart health.

A 2020 review of research suggests that EPO may have a beneficial effect on cholesterol levels, though some research was inconclusive.

Additional research is necessary to support the use of EPO to support heart health.

Speak with a doctor for advice on ways to improve your heart health and reduce the risk of heart disease and other conditions.

Reduce neuropathy symptoms

A 2018 review of research notes that animal studies have shown that fatty acids like linolenic acid may potentially help reduce neuropathy symptoms, such as:

  • hot and cold sensitivity
  • numbness
  • tingling
  • weakness

However, human clinical trials are necessary to show whether these results may extend to humans.

EPO is generally safe for most adults to use short term. The safety of long-term use isn’t clear.

Side effects of EPO are usually mild and may include:

  • stomach pain
  • diarrhea
  • nausea

The Food and Drug Administration (FDA) does not monitor supplement quality. When choosing EPO, research the supplement and the company selling the product. Choosing one that has been certified by a third party may be safer.

Taking the least amount possible may help prevent side effects.

There’s not enough research on EPO to determine its safety during pregnancy or when nursing.

In rare cases, EPO may cause an allergic reaction. Some symptoms of an allergic reaction are:

  • inflammation of the hands and feet
  • rash
  • difficulty breathing
  • wheezing

If you experience symptoms of an allergic reaction, seek immediate medical help.

EPO may interact with some medications.

If you take blood thinners, EPO may increase bleeding.

EPO may potentially increase blood pressure, so do not take it if you take blood pressure medication.

EPO may also affect how the HIV medication lopinavir (Kaletra) works.

While there’s not enough research to prove that EPO helps with sleep, some people report it helps them. EPO might help reduce inflammation and pain, which may help some people sleep better, though more research is necessary.

EPO may interact with some medications, so people who take blood thinners, some blood pressure medications, or the HIV treatment lopinavir should not take EPO. It is unclear whether it is safe to take during pregnancy.

Some research suggests that evening primrose oil (EPO) may benefit some conditions, such as acne and eczema, but more research is necessary.

While EPO is generally safe for adults to use, it is best to contact a doctor for advice before using it to treat an existing condition or symptom. It may not be suitable if you are taking medications such as blood thinners.

Your doctor can help weigh the risks and benefits of taking EPO and get advice about the proper dosage.