Borage Oil Side Effects

Reviewed by Terri Forehand RN
Borage with blue star-shaped flowers

Borage officinalis, commonly known as borage oil or star flower, is a flowering herb native to Europe and the Mediterranean. The herb is known for its medicinal and culinary benefits. If you are considering taking borage oil supplements, it is important to evaluate the possible risks of side effects along with the positive health benefits. All medicinal herbs have the potential for manifesting adverse reactions and must be used with care.

Potential Side Effects

All herbs have the potential for adverse side effects and drug interactions, including borage oil. A few mild borage oil side effects individuals may experience are digestive disturbances such as nausea, headaches and gastrointestinal upset; however, in some people more serious side effects may occur.


Memorial Sloane-Kettering Cancer Center (MSKCC) states that borage seeds contain the potentially toxic alkaloids amabilene and pyrrolizidine, which are considered to be toxic to the liver. Those who consume alcohol, or have liver or kidney disease are advised not to take borage due to the risk of liver damage. However, some commercial supplements are manufactured as alkaloid-free. The harmful alkaloids are extracted from the seeds before the oil is pressed into capsules. If you decide to take borage oil, it is recommended to take only certified alkaloid-free oil supplements.


MSKCC indicates that women who are pregnant or breastfeeding should not take borage oil due to its potential teratogenic effect in unborn fetuses and its ability to induce premature labor. Borage oil is sometimes used by health practitioners to ripen the cervix in preparation for labor; however, this method should only be used in full term pregnancies under the care and advice of a qualified physician.


There has been some confusion between borage and foxglove, resulting in accidental toxic poisoning. While borage is generally considered safe, foxglove contains a toxic property known as digitalis glycoside which can cause serious side effects or death.

Drug Interactions

Borage oil may interact with other medications. According to WebMD, if you take medications for any of the following medical reasons you should speak with a medical practitioner about the potential risks of drug interactions before taking borage oil:

  • Blood clots: Borage seed oil slows blood clotting and should not be used with other drugs that do the same. This includes Plavix, Coumadin, ibuprofen, aspirin, and Heparin.
  • Seizures or epilepsy: Anti-seizure medications such as phenobarbital, Tegretol, or Dilantin increase the breakdown of borage seed oil in the liver, leading to toxic side effects.
  • Inflammatory conditions: Borage oil is believed to have an anti-inflammatory effect. As a result, it should not be used in conjunction with NSAID medicines that reduce inflammation such as Advil, Motrin, Naproxen, and aspirin. Although more research is needed, it's believed by some that taking NSAIDS with borage oil may decrease its effectiveness.
  • Anesthesia: Borage oil may interact with anesthesia medications used during surgery.
  • Seizures: Healthline states that taking high dosages of borage may lead to seizures.

High-Quality Sources of Borage Oil

When purchasing commercially packaged borage oil, always look for certified alkaloid-free packaging marked by third party quality controls. Other things to look for in high-quality oils:

  • Certified organic packaging
  • Marked with a 'Fresh By' date
  • Packaged in light and heat resistant materials

Borage Dosage and Safety

Borage oil doses have been largely studied for only rheumatoid arthritis but there are some additional recommended guidelines. The Cleveland Clinic suggests a dose of 1 - 2 grams daily to treat eczema and up to three grams daily to treat rheumatoid arthritis. However, MSKCC states that toxic pyrrolidizine alkaloids can occur in as little as one daily gram of borage oil, so it's critical to purchase only alkaloid-free oil.

The exact dosage for therapeutic benefit will depend on the condition your medical practitioner wants to treat, generally from one to four grams. Always consult with your medical practitioner about therapeutic dosages before starting borage oil supplements.

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Borage Oil Side Effects