Safety and side effects

When taken in recommended amounts, flaxseed and flaxseed oil are generally safe to use. However, when taken in large amounts and with too little water, flaxseed can cause:

• Bloating
• Gas
• Diarrhea

Avoid use of flaxseed and flaxseed oil during pregnancy.

Occasionally, using flaxseed or flaxseed oil causes an allergic reaction.

Don't eat raw or unripe flaxseeds.

Because flaxseed oil might decrease blood clotting, stop using flaxseed oil two weeks before having elective surgery.

The evidence is mixed as to whether flaxseed or flaxseed oil has any effect on the prostate or the risk of prostate cancer.