What is flax?

The use of flax in cultural and traditional settings may differ from concepts accepted by current Western medicine. When considering the use of herbal supplements, consultation with a primary health care professional is advisable. Additionally, consultation with a practitioner trained in the uses of herbal/health supplements may be beneficial, and coordination of treatment among all health care providers involved may be advantageous.

Flax is also known as Linum usitatissimum, flaxseed, linseed, lint bells, linum, and winterlien.

Flax has been used most commonly as a laxative. Flax has also been used to reduce cholesterol levels, to slow prostate cancer growth before surgery, and topically for skin irritation.

Flax has not been evaluated by the FDA for safety, effectiveness, or purity. All potential risks and/or advantages of flax may not be known. Additionally, there are no regulated manufacturing standards in place for these compounds. There have been instances where herbal/health supplements have been sold which were contaminated with toxic metals or other drugs. Herbal/health supplements should be purchased from a reliable source to minimize the risk of contamination.

Flax may also have uses other than those listed in this medication guide.


Do not take flax internally without first talking to your doctor if you have a narrowing of the esophagus or another stomach area, an intestinal obstruction, or other stomach or intestinal problems. Since flax swells in the stomach, it may be dangerous if used by people with certain intestinal problems.

Do not take flax internally without first talking to your doctor if you have prostate problems or difficulty with urination.

Before taking flax, talk to your doctor, pharmacist, or health care professional if you have allergies (especially to plants), have any medical condition, or if you take other medicines or other herbal/health supplements. Flax may not be recommended in some situations.

Do not take flax without first talking to your doctor if you are pregnant or could become pregnant. It is not known whether flax will harm an unborn baby.

Do not take flax without first talking to your doctor if you are breast-feeding a baby. It is also not known whether flax will harm a nursing infant.

There is no information available regarding the use of flax by children. Do not give any herbal/health supplement to a child without first talking to the child’s doctor.

There are no restrictions on food, beverages, or activity while taking flax, unless otherwise directed by your health care provider.

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Seek emergency medical attention.

Symptoms of a flax overdose are not known.

No information is available regarding a missed dose of flax. Consult your doctor, pharmacist, or health care professional if you require further information.

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Side effects

Although rare, allergic reactions to flax may occur. Stop taking flax and seek emergency medical attention if you experience symptoms of a serious allergic reaction including difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives.

Other less serious side effects have not been reported, although they may occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome. You may report side effects to FDA at 1-800-FDA-1088.

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Do not take any other medication at the same time as flax without first talking to your doctor or health care provider. Flax may decrease the absorption of other drugs when taken together.

Interactions between flax and other prescription or over-the-counter medicines or herbal/health supplements may also occur. Talk to your doctor, pharmacist, or health care professional before taking flax if you are taking any other medicines or supplements.

Other Names

Flax Oil, Flax Seed Oil, and flax

Available Strengths & Dosages

Route Form Strength
oral capsule -

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Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04

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