Health Guide

Flaxseed oil

What is it?

Flaxseed oil is an herbal medicine taken by mouth for constipation (difficulty having a bowel movement), irritable bowel, inflammation (swelling and soreness) of the colon, stomach inflammation, and for bowels damaged by the frequent use of laxatives. Flax may be placed on the skin to treat redness and pain.

Other names for Flaxseed include: Flax, Flachs, Grain de Lin, and Lini semen.

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement)
  • are pregnant or plan to become pregnant while using this medicine
  • are breastfeeding
  • have any other health problems, such as high blood pressure or heart or blood vessel disease


Talk with your caregiver about how much Flaxseed oil you should take. The amount depends on the strength of the medicine and the reason you are taking Flaxseed oil. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Drug and Food Interactions:

Do not take Flaxseed oil without talking to your doctor first if you are taking:

  • Other medicines, as it may cause problems with absorption into the body of the other drugs when taken at the same time


  • Before taking Flaxseed oil, tell your doctor if you are pregnant or breastfeeding
  • Flaxseed oil works best when taken with food (1)
  • May cause ileus (intestinal blockage) (4)
  • May cause a thyroid problem (5)
  • Do not take more than 0.3 milligram/kilogram (6)
  • In inflammatory (sore and swollen) bowel conditions, Flaxseed must be presoaked before use (5)

Side Effects:

Stop taking your medicine right away and talk to your doctor if you have any of the following side effects. Your medicine may be causing these symptoms which may mean you are allergic to it.

  • Breathing problems or tightness in your throat or chest
  • Chest pain
  • Skin hives, rash, or itchy or swollen skin

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • No known side effects as long as enough water is taken with the seeds (1)


1. Blumenthal, Busse, Goldberg et al: Flaxseed. The Complete German Commission E monographs: Therapeutic Guide to Herbal Medicines, The American Botanical Council, Austin, TX; 1998.

2. Arjmandi BH, Khan DA, Juma S, et al: Whole flaxseed consumption lowers serum LDL-cholesterol and lipoprotein (a) concentrations in postmenopausal women. Nutr Res 1998;18(7):1203-1214.

3. Allman MA, Pena MM & Pang D: Supplementation with flaxseed oil versus sunflowerseed oil in healthy young men consuming a low fat diet: effects on platelet composition and function. Eur J Clin Nutr 1995; 49(3):169-178.

4. Brinker F: Herb Contraindications and Drug Interactions. Eclectic Institute Inc, Sandy, OR; 1997.

5. McGuffin M, Hobbs C, Upton R et al (eds): Linum usitatissimum L. American Herbal Products Association's Botanical Safety Handbook: guidelines for the safe use and labeling for herbs in commerce. CRC Press, Boca Raton, FL; 1997.

6. Bisset NG & Wichtl M (eds): Lini semen. Herbal Drugs and Phytopharmaceuticals: a handbook for practice on a scientific basis. Medpharm Scientific Publishers, CRC Press, Stuttgart, Germany; 1994:298-300.

Last Updated: 7/4/2018
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