Flaxseed is the seed from the plant Linum usitatissimum. The seed or the seed oil is used to make medicine. The information on this page concerns medicine made from the SEED only. There is a separate listing for flaxseed OIL.
People use flaxseed for many conditions related to the gastrointestinal (GI) tract, including ongoing constipation, colon damage due to overuse of laxatives, diarrhea, inflammation of the lining of the large intestine (diverticulitis), irritable bowel syndrome (IBS) or irritable colon, sores in the lining of the large intestine (ulcerative colitis), inflammation of the lining of the stomach (gastritis), and inflammation of the small intestine (enteritis).
Flaxseed is also used for disorders of the heart and blood vessels, including high cholesterol, “hardening of the arteries” (atherosclerosis), high blood pressure (hypertension), and coronary artery disease.
Flaxseed is also used for acne, attention deficit-hyperactivity disorder (ADHD), kidney problems in people with a disease called systemic lupus erythematosus (SLE), symptoms of menopause, and breast pain. It is also used for diabetes, obesity and weight loss, HIV/AIDS, depression, bladder infections, malaria, and rheumatoid arthritis.
Other uses include treatment of sore throat, upper respiratory tract infections (URTI), and cough.
Some people use flaxseed to lower their risk of getting weak bones (osteoporosis) and to protect against breast cancer, lung cancer, colon cancer, and prostate cancer.
Flaxseed is sometimes applied to the skin for acne, burns, boils, eczema, psoriasis, and to soothe inflammation.
Natural Medicines rates effectiveness based on scientific evidence
according to the following scale: Effective, Likely Effective, Possibly
Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and
Insufficient Evidence to Rate.
The effectiveness ratings for FLAXSEED are as follows:
More evidence is needed to rate of flaxseed for these uses.
Flaxseed is a good source of dietary fiber and omega-3 fatty acids. The fiber in flaxseed is found primarily in the seed coat. Taken before a meal, flaxseed fiber seems to make
people feel less hungry, so that they might eat less food. Researchers believe
this fiber binds with cholesterol in the intestine and prevents it from being
absorbed. Flaxseed also seems to make platelets, the blood cells involved in
clotting, less sticky. Overall, flaxseed’s effects on cholesterol and blood
clotting may lower the risk of “hardening of the arteries” (atherosclerosis).
Flaxseed is sometimes tried for cancer because it is broken down by the body
into chemicals called “lignans.” Lignans are similar to the female hormone
estrogen - so similar, in fact, that they compete with estrogen for a part in
certain chemical reactions. As a result, natural estrogens seem to become less
powerful in the body. Some researchers believe that lignans may be able to slow
down the progress of certain breast cancers and other types of cancers that
need estrogen to thrive.
For systemic lupus erythematosus (SLE), flaxseed is thought to improve kidney
function by decreasing the thickness of blood, reducing cholesterol levels, and
Flaxseed is LIKELY SAFE for most adults when
taken by mouth. Adding flaxseed to the diet might increase the number of bowel
movements each day. It might also cause gastrointestinal (GI) side effects such
as bloating, gas, abdominal pain, constipation, diarrhea, stomachache, and
nausea. Higher doses are likely to cause more GI side effects.
There is some concern that taking large amounts of flaxseed could block the
intestines due to the bulk-forming laxative effects of flaxseed. Flaxseed
should be taken with plenty of water to prevent this from happening.
Taking flaxseed extracts that contain lignans in concentrated form is POSSIBLY
SAFE. Lignans are the chemicals in flaxseed that are thought to be
responsible for many of the effects. Some clinical research shows that a
specific flaxseed lignan extract (Flax Essence, Jarrow Formulas) can be safely
used for up to 12 weeks.
Products that contain partially defatted flaxseed, which is flaxseed with less
alpha-linolenic acid content, are available. Some men choose these products
because they have heard that alpha-linolenic acid might raise their risk of
getting prostate cancer. It’s important to remember that the source of the
alpha-linolenic acid is key. Alpha-linolenic acid from dairy and meat sources
has been positively associated with prostate cancer. However, alpha-linolenic
acid from plant sources, such as flaxseed, does not seem to affect prostate
cancer risk. Men should not worry about getting alpha-linoleic acid from
flaxseed. On the other hand, there is a concern that partially defatted
flaxseed might raise triglyceride levels too much. Triglycerides are a type of
Raw or unripe flaxseed is POSSIBLY UNSAFE. Flaxseed in these forms
is thought to be poisonous.
Pregnancy and breast-feeding: Taking flaxseed by mouth
during pregnancy is POSSIBLY UNSAFE. Flaxseed can act like the hormone estrogen. Some healthcare providers worry that this might harm the pregnancy, although to
date there is no reliable clinical evidence about the effects of flaxseed on
pregnancy outcomes. The effect of flaxseed on breast-fed infants is unknown at
this time. Stay on the safe side, and don’t use flaxseed if you are pregnant or
Bleeding disorders: Flaxseed might slow clotting. This raises the
concern that it could increase the risk of bleeding in people with bleeding
disorders. Don’t use it, if you have a bleeding disorder.
Diabetes: There is some evidence that flaxseed can lower blood sugar
levels and might increase the blood sugar-lowering effects of some medicines
used for diabetes. There is a concern that blood sugar could drop too low. If you
have diabetes and use flaxseed, monitor your blood sugar levels closely.
Gastrointestinal (GI) obstruction: People with a bowel obstruction, a
narrowed esophagus (the tube between the throat and the stomach), or an
inflamed (swollen) intestine should avoid flaxseed. The high fiber content of
flaxseed might make the obstruction worse.
Hormone-sensitive cancers or conditions: Because flaxseed might act
somewhat like the hormone estrogen, there is some concern that flaxseed might
make hormone-sensitive conditions worse. Some of these conditions include
breast, uterine, and ovarian cancer; endometriosis; and uterine fibroids.
However, some early laboratory and animal research suggests that flaxseed might
actually oppose estrogen and might be protective against hormone-dependent
cancer. Still, until more is known, avoid excessive use of flaxseed if you have
a hormone-sensitive condition.
High triglyceride levels (hypertriglyceridemia): Partially defatted
flaxseed (flaxseed with less alpha linolenic acid content) might increase
triglyceride levels. If your triglyceride levels are too high, don’t take
Low blood pressure (hypotension): Flaxseeds might lower diastolic blood
pressure. Theoretically, taking flaxseeds might cause blood pressure to become
too low in individuals with low blood pressure.
High blood pressure (hypertension): Flaxseeds might lower diastolic
blood pressure. Theoretically, taking flaxseeds might cause blood pressure to
become too low in individuals with high blood pressure who are taking blood
Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.
There is some evidence that flaxseed might interfere with the body's ability to take in and use acetaminophen. It's not known, though, whether this interaction is important.
Bacteria in the intestine convert some of the chemicals in flaxseed into lignans, which are thought to be responsible for many of the possible benefits of flaxseed. However, because antibiotics kill these bacteria, lignans might not be formed as usual. This might alter the effects of flaxseed.
Flaxseed can act like the female hormone estrogen. It can compete with estrogens that are included in birth control pills and hormone replacement treatments. Healthcare providers are concerned that flaxseed might make these estrogen-containing drugs less effective.
There is some evidence that flaxseed might interfere with the body's ability to take in and use furosemide. It's not known, though, whether this interaction is important.
There is some evidence that flaxseed might interfere with the body's ability to take in and use ketoprofen. It's not known, though, whether this interaction is important.
Some evidence suggests that flaxseed can lower blood sugar levels. Diabetes medications are also used to lower blood sugar. Taking flaxseed along with diabetes medications might cause your blood sugar to become too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.
Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.
Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), amlodipine (Norvasc), hydrochlorothiazide (HydroDIURIL), furosemide (Lasix), and many others.
Flaxseed can act like a laxative. There is some concern that it might interfere with the body's ability to absorb medications taken by mouth because it might sweep them out of the digestive tract too quickly. To avoid this problem, take medications an hour before or two hours after taking flaxseed.
Flaxseed might slow blood clotting. Taking flaxseed along with medications that also slow clotting might increase the chances of bruising and bleeding.
Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.
There is some evidence that flaxseed might interfere with the body's ability to take in and use metoprolol. It's not known, though, if this interaction is important.
Flaxseed might lower blood sugar. If it is taken along with other herbs and supplements that might lower blood sugar, blood sugar might become too low in some people. Some herbs and supplements that might lower blood sugar include alpha-lipoic acid, bitter melon, chromium, devil's claw, fenugreek, garlic, guar gum, horse chestnut, Panax ginseng, psyllium, Siberian ginseng, and others.
Flaxseed might lower blood pressure. It has the potential to have additive effects with other herbs and supplements that also lower blood pressure, and blood pressure may become too low. Other herbs and supplements that can lower blood pressure include andrographis, casein peptides, cat's claw, coenzyme Q-10, fish oil, L-arginine, lyceum, stinging nettle, theanine, and others.
Flaxseed can increase the amount of time it takes for blood to clot. Taking flaxseed along with other herbs and supplements that slow blood clotting might increase the risk of bleeding and bruising in some people. Some of these herbs include angelica, clove, danshen, garlic, ginger, ginkgo, Panax ginseng, and others.
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