Evening primrose oil and menopause: does it affect hot flushes?

Evening primrose (Oenothera biennis) is a plant native to North America. Its yellow flowers open towards the end of the day, hence its English name, evening primrose. Its oil is extracted from the small seeds inside its seed pods.

What sets this flower apart is its gamma-linolenic acid, or GLA, content. This omega-6 fatty acid is uncommon in the everyday diet. It is mainly found in a few plant oils, such as borage and blackcurrant seed oils. GLA is a component of cell membranes, particularly those in the skin, and is a precursor to molecules involved in regulating inflammation.

This composition explains the interest in evening primrose for the skin and certain discomforts women experience, from premenstrual syndrome to menopause. At Jolly Mama, it is available in capsule form as Evening Primrose Mama.

Hot flushes are among the most common symptoms of menopause. Several randomised trials, most conducted in Iran, have tested oral evening primrose oil, usually at around one gram per day for six to eight weeks [1] [3] [6]. To understand their results, it helps to know what these trials measured.

Intensity, frequency, duration: three different measures

A hot flush can be assessed in three ways:

• Frequency refers to the number of episodes per day.
• Intensity, or severity, refers to how strongly a symptom is felt, as rated by the participant on a scale.
• Duration measures how long each episode lasts.

These three measures do not necessarily change together. A supplement may make hot flushes a little less difficult without reducing their number. Another key point: in these trials, the placebo group often improves too, sometimes quite markedly [1]. Only a comparison between the two groups can therefore show what is genuinely attributable to evening primrose.

Intensity: its main potential benefit

The most frequently cited trial was published in 2013. It followed 56 women in menopause aged 45 to 59, who received evening primrose oil capsules or a placebo for six weeks. All three measures of hot flushes improved in both groups. But intensity fell significantly more with evening primrose: by 42% on average, compared with 32% with placebo [1]. The difference between the groups was not significant for frequency or duration.

Another encouraging finding: the same trial found a greater benefit with evening primrose in terms of how much hot flushes affected daily life, including social activities, relationships and intimate life [1].

A meta-analysis published in 2024 [2], bringing together the available trials, points in the same direction: hot flushes were less intense with evening primrose than with placebo when it was taken for less than six months. However, it found no difference in frequency or duration, and its authors call for further studies to confirm these results.

Frequency: an effect not demonstrated

As for the number of hot flushes, however, evening primrose did not perform notably differently from placebo. In a 2021 trial [3] involving 170 women in menopause over eight weeks, neither the frequency, intensity nor duration of hot flushes decreased significantly with evening primrose.

Two meta-analyses also point in this direction. The first [4], published in 2020, brings together five trials involving 402 women in perimenopause or menopause: it found no effect of evening primrose on the frequency or intensity of hot flushes and night sweats, only a slight reduction in the overall menopause symptom score. The second [5], published in 2025 and covering six trials, found shorter episodes with evening primrose, but no significant reduction in their frequency or intensity. Its authors also rated the quality of the evidence as moderate to low.

Night sweats: an encouraging result that needs confirmation

The 2021 trial found an interesting result [3]: night sweats were less frequent and less intense in the evening primrose group than in the control group. This finding deserves further investigation, although it comes from a single-blind trial.

Evening primrose oil can be an additional option. Trials suggest it may make hot flushes a little less difficult to cope with, while being very well tolerated [1] [2]. To use it effectively, it is also important to understand what it cannot do for you!

• It is not a treatment for menopause: evening primrose is a food supplement, not a medicine. The trials concern an effect on the intensity of hot flushes, not the disappearance of symptoms [1] [2].
• It does not replace menopause hormone therapy: menopause hormone therapy remains the standard treatment for hot flushes that significantly disrupt daily life. Its potential benefits, risks and contraindications should be discussed individually with your doctor, gynaecologist or midwife.
• It does not act like a hormone: evening primrose is not a source of phytoestrogens, and no hormonal effect has been demonstrated in women in menopause.
•  Its effects still need to be confirmed in larger studies: The trials involve small groups over a few weeks, and several were not double-blind. All the meta-analyses call for larger studies [2] [4] [5].

Beyond hot flushes, evening primrose has also been studied for other discomforts women may experience, worth knowing about if you are in perimenopause and still have periods. In a three-month placebo-controlled trial involving 80 students, premenstrual syndrome symptoms were markedly less severe with evening primrose oil [9]. For cyclical breast pain, a six-month trial found a greater reduction in pain than with placebo, comparable to that seen with vitamin E [10].

Alongside evening primrose, there are other approaches to managing hot flushes, from lifestyle measures to plants. We have brought them together in our guide ‘ Hot flushes and night sweats: natural approaches ’. For an overview of the plants studied during this stage of life, you can also visit our page ‘ Menopause: which plants? ».

The fall in oestrogen levels around menopause does not only cause hot flushes. Skin also tends to become drier, thinner and less elastic. This is where evening primrose, with its high GLA content, is of particular interest.

A placebo-controlled trial [7], published in 2005, followed 40 healthy adults, women and men aged 32 to 56, for twelve weeks. With evening primrose oil, skin hydration, elasticity, firmness and roughness improved compared with placebo. A promising result.

The available trials concern the skin, not intimate mucous membranes. For vaginal dryness, local care remains the first approach: vaginal moisturisers and lubricants, or a local treatment prescribed by a healthcare professional if needed. Speak to your midwife or gynaecologist about it.

For those who would like to include evening primrose oil in their routine, Evening Primrose Mama offers an easy-to-take option for everyday use.

To care for both your comfort during menopause and your skin, you can combine two approaches.

Péri Support was formulated to support you through menopause. It combines sage, which notably helps reduce night sweats, with shatavari, saffron and milk thistle. It does not contain evening primrose. The two supplements can be taken together. You can find all our supplements designed for menopause in our menopause collection.

Before taking several supplements together, including evening primrose oil, ask your doctor or pharmacist for advice, particularly if you are receiving treatment.

Side effects observed in trials

The good news is that evening primrose oil has been well tolerated in clinical trials. Reported side effects have generally been mild: nausea, headaches or digestive discomfort [2]. Taking the capsules with a meal may help limit digestive discomfort if you experience it.

Interactions to be aware of

Anticoagulants and antiplatelet medicines: evening primrose oil could increase the risk of bleeding in people taking blood-thinning medication, such as warfarin, clopidogrel or aspirin. This risk is largely theoretical, but it warrants medical advice before taking it.

Surgery: for the same reason, it is generally advised to stop taking evening primrose about two weeks before a planned operation. Tell your surgeon or anaesthetist that you are taking it.

Epilepsy and certain psychiatric medicines : cases of seizures have previously been reported in people taking evening primrose alongside medicines in the phenothiazine family. The link is still debated, but caution is advised if you have epilepsy or take this type of medicine.

When should you seek medical advice?

Speak to your doctor, gynaecologist, midwife or pharmacist before taking evening primrose oil if:

• you are receiving menopause hormone therapy;
• you have a history of hormone-dependent cancer;
• you take long-term medication or have a blood-clotting disorder;
• your hot flushes disrupt your sleep or daily life. 

Finally, any bleeding after menopause should always prompt you to seek medical advice, regardless of which supplement you are taking.