Borage Oil Side Effects

Omega-6 fatty acids are essential for health, but because the body cannot produce them, they must be obtained through diet or supplements. Some omega-6 fatty acids promote inflammation, according to the University of Maryland Medical Center (UMMC), but gamma-linoleic acid does not. In fact, GLA may actually decrease inflammation in the body. Borage seed oil is a good source of GLA, and may be useful for treating rheumatoid arthritis, according to the University of Michigan Health System (UMHS). Some side effects are possible with this supplement.

Minor Side Effects

Gastrointestinal side effects are possible when taking borage seed oil, as noted by the UMHS. These effects can include gas, belching, bloating, indigestion, nausea and diarrhea. Some people also experience headaches when consuming this substance.

Increased Bleeding

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Taking borage oil may increase the risk of abnormal bleeding. If you take medications with blood-thinning effects, talk with a health care provider before taking borage oil or any other omega-6 fatty acid supplements, as advised by the UMMC. Some of these medications include warfarin, heparin, clopidogrel, ibuprofen and aspirin.

Pregnancy Considerations

Pregnant women should not take borage seed oil because it might have harmful effects on the fetus, as explained by the UMMC. This may hold true for other sources of GLA as well. Additionally, GLA supplements may cause premature labor.

Considerations for Men

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Laboratory research indicates that omega-6 fatty acids stimulate the growth of prostate tumor cells, according to the UMMC. Men who have prostate cancer or who are at increased risk of this disorder should not take borage seed oil supplements.

Allergic Reaction

As with any herbal supplement, some people may experience an allergic reaction to borage seed oil. Allergy signs may include itching, hives, a rash, tingling, or swelling in the mouth or throat, facial or hand swelling, difficulty breathing and chest tightness. An allergic reaction to borage oil should be considered a medical emergency.


Some people have developed seizures while taking evening primrose oil, which also contains GLA. Although these incidents did not involve borage seed oil, the UMMC cautions that individuals with seizure disorders should not take any type of omega-6 fatty acid supplement. Because some of the reports involved patients under anesthesia, anyone scheduled for surgery requiring anesthesia should stop taking omega-6 fatty acid supplements at least two weeks beforehand.