Evening Primrose Oil Side Effects

Evening primrose is a herb that is popular for its health benefits. It is a wild flowering plant, which is believed to be native to Mexico and Central America. This plant belongs to the genus Oenothera, which consists of around 125 species that are commonly known as evening primrose, sun cups or sundrops. While most species of evening primrose produce yellow flowers, there are some with white, pink, red and purple flowers. However, common evening primrose, (Oenothera biennis) or evening star possesses yellow flowers. The name of this plant - evening primrose, is derived from its flowers that bloom in the evening. Evening primrose plants have been used by humans for a very long time. This herb is believed to have strong healing powers and so is used in treating various ailments. This plant is so popular for its health benefits, that it is also called King's cure-all.


Earlier, native Americans used to make an evening primrose infusion, which was used as an astringent as well as a sedative. This herb was also widely accepted as an effective remedy for asthmatic cough and gastrointestinal disorders. Evening primrose was very popular for healing bruises and wounds. Even today, it is used as a herbal medicine, mostly in the form of evening primrose oil supplements. This oil is extracted from the mature seeds of this plant. Evening primrose oil is very rich in gamma-linolenic acid, which is an essential fatty acid. It is believed that most of the benefits of evening primrose oil are due to the presence of gamma-linolenic acid. In fact, this oil is considered one among the safest sources of gamma-linolenic acid.

Evening primrose oil supplements are used to ease symptoms related to premenstrual syndrome, endometriosis and fibrocystic breasts. It is also found to be effective in preventing and controlling the symptoms of diabetic neuropathy. Evening primrose oil is used in treating eczema, acne, rosacea, rheumatoid arthritis, osteoporosis, ulcerative colitis and various other medical conditions. It is also believed to be beneficial in reducing cholesterol, thereby curbing the risk of heart disease. Scroll down to know more about some evening primrose oil side effects.


Even though, evening primrose oil is found effective for many of the conditions stated above, there is no substantial scientific evidence to prove the efficacy of the health benefits of this herb. Various studies have been conducted in this regard and some of them suggest that this oil is possibly effective for relieving breast pain. If combined with calcium supplements, evening primrose oil may prove useful for countering osteoporosis too. As of now, there is no scientific backing for other evening primrose oil benefits. While some of the users find it effective for certain ailments, others do not. Evening primrose oil is also said to be safe and free of side effects. Though rare, this herbal product may cause certain side effects. In most cases, primrose oil side effects are linked to excess use, impurities in the oil and improper usage. The following are some of the possible evening primrose oil side effects.

• Usually, mild side effects like headache, nausea, upset stomach and loose stools, are experienced by some of the users. Most of these side effects can be avoided by starting the treatment in small doses, that has to be taken with meals.
• Allergic reactions, like skin rash is possible in evening primrose oil users, who have a history of allergies.
• Low blood pressure is also reported to be one of the evening primrose oil side effects. So, if you have hypotension, avoid using this herb.
• Evening primrose oil used to treat sunburn may cause skin rash in some people.
• Studies show that this oil may increase frequency of seizures in patients with seizure disorder and also in those, who have undergone surgery under anesthesia.
• It may also increase the risk of epilepsy in schizophrenic patients, who are taking anti-psychotic medication.
• Those who are using blood thinners must refrain from taking this herb, as it can increase the risk of bleeding.

These are some of the possible evening primrose oil side effects. This herbal product may cause drug interactions too. So, avoid using evening primrose oil, if you are taking blood thinning medication, antidepressants, hypertension drugs, phenothiazines (for treating schizophrenia) and medication for seizures. Even drugs used during surgery, may interact with primrose oil. So, those who are planning to undergo any surgery must stop taking this herbal product, at least a week before the date of surgery. Those with liver diseases and/or diabetes should not use this oil. Pregnancy and breastfeeding are two other conditions, wherein women must avoid this herbal product.

Even though, evening primrose oil is considered a safe herbal product with many health benefits, it is not approved by the FDA. However, you may take this herb as per the instructions of a qualified herbal practitioner. You may also seek the opinion of your doctor, before starting the herbal treatment. If you experience any side effects, including allergic reactions, it will be better to discontinue its use. In case of severe allergic reactions (very rare), seek immediate medical attention. In case of overdose too, contact your doctor immediately.

Disclaimer: This article is for informational purposes only and should not be used as a replacement for expert medical advice.