While discussing the side effects of Flaxseed oil, it is important to distinguish between its two different uses.  Flaxseed oil is often used as a cooking ingredient or just to replace hydrogenated vegetable oils.  In these situations, Flaxseed oil is very safe and there are many health benefits when it is used to replace less healthy oils. Flaxseed oil is also used as a supplement, and consumed in much higher concentrations than is used for normal cooking.  It is Flaxseed oils use as a supplement that will cause some people to experience side effects.

Flaxseed oil is often taken in high doses for a few different reason.  The main reason is just as nutrient supplement.  Flaxseed oil is taken as a supplement mainly for Omega-3 and Omega-6 fatty acids as well as it´s high fiber content.  Flaxseed oil is often taken to prevent or cure certain ailments including rheumatoid arthritis, atherosclerosis and less commonly for anxiety.  There has been no scientific research that supports Flaxseed oil as preventing or curing any of these conditions, and at the doses typically taken, serious side effects may occur.

The most common side effects of Flaxseed oil occur when individuals take more than 25 grams per day (about 4 teaspoons) for a few months.  The most common side effect for those taking more than 25 grams per day is diarrhea and abdominal cramps.  If the individual continues to take high doses, other side effects and symptoms may appear including those associated with malnutrition and dehydration.

There are more serious possible side effects of Flaxseed oil.  These are either very rare, or have only been shown to occur in animals.  These side effects also only need to be noted when talking about taking Flaxseed oil in high doses like a supplement, and are not a concern when Flaxseed oil is used during cooking.

Some preliminary research has shown a link between alpha-linolenic acid, a substance found in Flaxseed oil and prostate cancer.  However, this research has only shown to be conclusive in regards to the animal form of the chemical, and not the form found in Flaxseed oil, which is slightly different in structure.

Flaxseed oil should also be avoided for those that are having surgery in the near future, or shortly after surgery.  It should also be discontinued for any person taking any medications for blood clotting as one of the side effects of Flaxseed oil is a change in clotting performance.

Flaxseed oil is a great additive for cooking, or as a replacement for hydrogenated vegetable oils.  However, like most supplements, taking them at higher doses can lead to many serious side effects.  In the case of Flaxseed oil these include diarrhea, malnutrition and dehydration.  Because of some side effects, Flaxseed oil should also be avoided during pregnancy, breastfeeding, or around the time of a surgery.