flaxseed oil

Flaxseed oil is a dietary supplement pressed from flaxseed (also known as linseed). Its primary component is alpha-linolenic acid (ALA), an omega-3 fatty acid that comes from plants. It is sold as a liquid oil and in softgel capsules.

NCCIH notes that flaxseed and flaxseed oil supplements are marketed for the heart, brain, and immune system, but the supporting research is of varying quality and limited overall. NCCIH indicates that flaxseed oil supplements do not appear to aid weight loss. Some research suggests that flaxseed oil supplements containing ALA might improve fasting measures and insulin resistance in pregnant people with gestational diabetes, while the picture for type 2 diabetes and other forms of diabetes remains unclear and needs more study. The available evidence does not establish that flaxseed oil prevents, treats, or cures any condition.

NCCIH does not list a specific recommended dose for flaxseed oil supplements, and the amount of ALA per serving varies by product. Speak with a clinician or pharmacist before starting flaxseed oil to determine whether it is appropriate for you, particularly if you are pregnant, breastfeeding, have a health condition, or take any medication.

According to NCCIH, limited amounts of flaxseed may be safe for short-term use of up to about 6 months. Flaxseed oil's safety during pregnancy is not well established; some studies suggest it may be possibly unsafe, though the evidence is not conclusive, and little is known about its use while breastfeeding. Avoid eating raw or unripe flaxseed, which can contain potentially toxic compounds. If you take any medication, consult your health care provider before using flaxseed oil, because some supplements and drugs can interact in harmful ways.

NCCIH reports that higher doses of flaxseed or flaxseed oil supplements can lead to uncomfortable digestive effects, including bloating, a sense of fullness, and diarrhea.

NCCIH explains that there are theoretical grounds to suspect flaxseed or flaxseed oil could interact with certain medications, including anticoagulant and antiplatelet (blood-thinning) drugs. Since supplements and medicines can sometimes interact in harmful ways, talk with your health care provider before combining flaxseed oil with any prescription or over-the-counter medication.