What Is Flaxseed Oil?

In This Article
View All
In This Article

Flaxseed oil is a supplement rich in an omega-3 fatty acid called alpha-linolenic acid (ALA). ALA is an essential fatty acid humans need and that is believed to offer many protective health benefits. Largely because of this, flaxseed oil may be used to try help manage and prevent several conditions.

Flaxseed oil, also known as linseed oil and flax oil, is available in oil and capsule form. The oil comes from the seeds of the flax plant (Linum usitatissimum L.), an annual plant grown around the world, including the U.S. Flax and flaxseeds can also be used for different benefits. For example, fiber from the plant is used to make linen. But flaxseed oil is what is available in supplement form.

A woman holds out three supplements in one hand while holding a glass of water in the other hand

Maryna Terletska / Getty Images

Benefits of Flaxseed Oil

Flaxseed oil is thought to help in a variety of functions, including the formation of new bone tissue, the ability for blood to clot in a timely manner so bleeding stops, and the increase of tears so your eyes don't get dry.

Flaxseed oil is also believed to potentially have specific effects on certain conditions.

May Reduce Inflammation

Chronic inflammation is associated with health conditions such as heart disease, cancer, and type 2 diabetes. Research has shown that flaxseed oil may help reduce inflammation.

One small study showed that people with type 2 diabetes and coronary heart disease who took 1,000mg of flaxseed oil twice a day for 12 weeks experienced a significant reduction in an inflammatory marker called C-reactive protein.

A review of multiple studies concluded that taking flaxseed oil reduced inflammation in people with obesity. However, there was no inflammation reduction seen in people who were considered generally healthy.

Some research disagrees with the connection between flaxseed oil and inflammation reduction, but most research does show evidence of it.

May Protect Heart Health

There are several factors that can affect heart health, including blood pressure and cholesterol levels.

Although more research is needed, one study showed that consuming flaxseed oil had positive effects on lowering systolic blood pressure—the top number of your blood pressure reading—among people with metabolic syndrome. If you have high blood pressure, lowering it can help reduce the risk of heart disease, heart attack, and stroke.

When it comes to reducing cholesterol levels, a small study found flaxseed oil lowered
low-density lipoprotein (LDL) cholesterol, a type of cholesterol associated with artery hardening and heart disease. However, other research shows that there is no positive effect on LDL cholesterol.

If you already have heart disease, flaxseed oil may be able to help protect you against complications from the disease. People with heart disease who took 1.2g more of ALA a day had a 20% reduced risk of fatal coronary heart disease. While flaxseed is high in ALA, it is unclear whether the flaxseed oil would be able to offer this positive effect.

May Aid in Diabetes Management

Insulin is a hormone that regulates blood sugar. High insulin levels are associated with type 2 diabetes. One study found that people with diabetes and coronary heart disease who took flaxseed oil had a significant reduction in insulin levels. However, most research shows no benefit of using flaxseed oil for type 2 diabetes.

A type of diabetes that might have more promise of reaping benefits from flaxseed oil is gestational diabetes. People can develop gestational diabetes when they are pregnant, and it can negatively impact your pregnancy and your baby's health. It also puts you at increased risk for later developing type 2 diabetes.

One small study found that people with gestational diabetes who were 24-28 weeks pregnant had reduced levels of insulin and glucose after taking 1g of flaxseed oil twice a day for six weeks.

Editor's Note: Flaxseed oil or the ALA it contains has been studied in many conditions. While some findings suggest that flaxseed oil could have some benefit, the research is insufficient for the following conditions:

  • Breast cancer
  • Ulcerative colitis
  • Attention deficit-hyperactivity disorder (ADHD)
  • Burns
  • Carpal tunnel syndrome
  • Chronic kidney disease
  • Diabetic foot ulcers
  • Dry skin
  • Polycystic ovary syndrome (PCOS)
  • Parkinson disease

How To Take Flaxseed Oil

Flaxseed oil is available in oil or capsule form. Most clinical research into flaxseed oil is done using gel capsules. As an oil, it can replace other types of oil in salad dressings, dips, and sauces. It can also be added to smoothies, milk, and yogurt. Flaxseed oil should not be used for frying because it breaks down at higher temperatures.

Store the flaxseed oil and capsules in the refrigerator or another cool, dark place as it can degrade if exposed to light, air, or heat.


Flaxseed oil has most often been used in 1,000mg to 2,000mg doses for up to six months. The recommended daily intake of ALA is 1,100mg for women and 1,600mg for men. This recommendation is based on the overall intake of the nutrient, not specifically on supplement dosage.

Is Flaxseed Oil Safe?

Generally, flaxseed oil is safe as long as it is consumed in moderation.

If you're pregnant, talk with a healthcare provider before taking flaxseed oil as some research suggests that taking it in the second or third trimester can increase the risk of premature birth.

Because there isn't enough evidence about flaxseed oil's safety when breastfeeding, it is advised to avoid using it during that time.

Potential Drug Interactions

Flaxseed oil might decrease blood clotting, lower blood pressure, or lower blood sugar, so possible drug interactions include:

  • Anticoagulant and anti-platelet drugs: Combined with flaxseed oil, may
    increase the risk of bleeding
  • Blood pressure medications: Combined with flaxseed oil, might decrease blood pressure too much
  • Zetia (Ezetimibe): Combined with flaxseed oil, the cholesterol-lowering medication may reduce the amount of ALA absorbed from the oil

It’s always best to talk with a healthcare provider before starting any supplement to be sure it’s safe for you.

If you take other supplements that may have blood pressure-lowering or anti-clotting effects, you should also consult with a healthcare provider. Mixing the supplements could make blood pressure go too low or the anticoagulant effect too strong.

What To Look For

When purchasing flaxseed oil look for the following:

  • Opaque bottles because light can damage the nutrients and cause it to go rancid
  • Check the “Best If Used By” date to ensure you’re buying a fresh product
  • A brand that does third-party testing (the U.S. Food and Drug Administration doesn't regulate supplements, so this testing ensures the product is safe)

Can You Take Too Much Flaxseed Oil?

There is not enough evidence to say how much flaxseed oil is too much. What is known is that doses as high as 24g a day for up to seven weeks have been used safely.

Side Effects of Flaxseed Oil

Few side effects of flaxseed oil have been reported. When side effects do happen, they can include:

While rare, a severe allergic reaction can develop after taking flaxseed oil.

A Quick Review

Flaxseed oil is made by extracting the oil from the seeds of the flax plant and can be purchased in oil or capsule form. Flaxseed oil may reduce inflammation and be beneficial for certain chronic conditions, like heart disease and diabetes, but more research is needed to confirm the health
benefits of flaxseed oil. As with any supplement, it is best to talk with a healthcare provider before taking flaxseed oil to make sure it is safe for you.

Was this page helpful?
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kim K, Nam YA, Kim HS, Hayes AW, Lee B. α-Linolenic acid: Nutraceutical, pharmacological and toxicological evaluation. Food Chem Toxicol. 2014;70:163-78. doi:10.1016/j.fct.2014.05.009

  2. Saleem MH, Ali S, Hussain S, et al. Flax (Linum usitatissimum L.): A potential candidate for phytoremediation? Biological and economical points of view. Plants (Basel). 2020;9(4):496. doi:10.3390/plants9040496

  3. Natural Medicines. Flaxseed oil.

  4. Furman D, Campisi J, Verdin E, et al.Chronic inflammation in the etiology of disease across the life spanNat Med. 2019;25(12):1822-1832.doi:10.1038/s41591-019-0675-0

  5. Raygan F, Taghizadeh M, Mirhosseini N, et al. A comparison between the effects of flaxseed oil and fish oil supplementation on cardiovascular health in type 2 diabetic patients with coronary heart disease: A randomized, double-blinded, placebo-controlled trialPhytother Res. 2019;33(7):1943-1951. doi:10.1002/ptr.6393

  6. Ren GY, Chen CY, Chen GC, et al. Effect of flaxseed intervention on inflammatory marker c-reactive protein: a systematic review and meta-analysis of randomized controlled trials. Nutrients. 2016;8(3):136.doi:10.3390/nu8030136

  7. Centers for Disease Control and Prevention. Heart disease.

  8. Mahmudiono T, Jasim SA, Karim YS, et al. The effect of flaxseed oil consumption on blood pressure among patients with metabolic syndrome and related disorders: A systematic review and meta‐analysis of randomized clinical trials. Phytother Res. 2022;36(10):3766-3773. doi:10.1002/ptr.7566

  9. Centers for Disease Control and Prevention. High blood pressure symptoms and causes.

  10. Taheri S, Keyvandarian N, Mortazavi M, Hosseini S, Naini A. Effect of Omega-3 fatty acids on blood pressure and serum lipids in continuous ambulatory peritoneal dialysis patients. J Res Pharm Pract. 2015;4(3):135.doi:10.4103/2279-042X.162356

  11. Centers for Disease Control and Prevention. Gestational diabetes.

  12. Vieira SA, McClements DJ, Decker EA. Challenges of utilizing healthy fats in foods. Advances in Nutrition. Adv Nutr. 2015;6(3):309S-317S.doi:10.3945/an.114.006965

  13. National Institutes of Health. Omega-3 fatty acids.

  14. National Center for Complementary and Integrative Health. Flaxseed and flaxseed oil.

  15. U.S. Food and Drug Administration. FDA 101: Dietary supplements.

Related Articles