Side Effects of Flaxseeds

Flaxseeds are a healthy food, but they can also have side effects. Here are 6 to be aware of.

Allergic reaction

Some people are allergic to flaxseeds. Symptoms can include hives, swelling, and difficulty breathing.

Slowed blood clotting

Flaxseeds contain omega-3 fatty acids, which can slow down blood clotting. This can be a problem for people who are taking blood thinners or who have bleeding disorders.


Flaxseeds are high in fiber, which can help with constipation. However, too much fiber can also cause constipation.

Intestinal obstruction

If flaxseeds are not ground up, they can clump together and block the intestines. This is a rare but serious side effect.

Bloating and gas

Flaxseeds can cause bloating and gas in some people. This is usually not serious and goes away on its own.

Interaction with medications

Flaxseeds can interact with some medications, such as blood thinners and diabetes medications. Talk to your doctor before taking flaxseeds if you are taking any medications.

Safety during pregnancy and lactation

Flaxseeds are safe for most people to eat, but they should be avoided during pregnancy and lactation.