Methionine is an amino acid. Amino acids are the building blocks that our bodies use to make proteins. Methionine is found in meat, fish, and dairy products. It plays an important role in the many functions within the body.
Methionine is commonly taken by mouth to treat liver disorders and viral infections along with many other uses. But there is limited scientific research that supports these uses.
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In acetaminophen poisoning, methionine prevents the breakdown products of acetaminophen from damaging the liver. It may also act as an antioxidant and help to protect damaged tissues.
Methionine is LIKELY SAFE when taken by mouth in amounts commonly found in foods. It is POSSIBLY SAFE when taken by mouth or given intravenously (by IV) under the supervision of a healthcare professional. In some people, methionine may cause headache, heartburn, nausea, diarrhea, dizziness, or drowsiness.
Don't treat yourself with methionine. It is POSSIBLY UNSAFE to use methionine by mouth or intravenously to self-medicate. Too much methionine can cause brain damage and death. Methionine can increase blood levels of homocysteine, a chemical that may cause heart disease. Methionine might also promote the growth of some tumors.
Special Precautions & Warnings:Children: Methionine is LIKELY SAFE for children when given by mouth in amounts commonly found in foods. It is POSSIBLY SAFE when given by IV, but only under the supervision of a healthcare professional. Methionine is POSSIBLY UNSAFE when given by IV into infants who are also receiving parenteral nutrition (nutrition through the vein).
Pregnancy and breast-feeding: Methionine is LIKELY SAFE when taken by mouth in amounts commonly found in foods. But there is not enough information about the safety of taking methionine in larger doses than those commonly found in foods. Stay on the safe side and avoid use.
Acidosis: Methionine can cause changes in acidity of the blood and should not be used in people with a condition called acidosis.
"Hardening of the arteries" (atherosclerosis): There is some concern that methionine might make atherosclerosis worse. Methionine can increase blood levels of a chemical called homocysteine, especially in people who don't have enough folate, vitamin B12, or vitamin B6 in their bodies, or in people whose bodies have trouble processing homocysteine. Too much homocysteine is linked to an increased risk for diseases of the heart and blood vessels.
Liver disease, including cirrhosis: Methionine might make liver disease worse.
Methylenetetrahydrofolate reductase (MTHFR) deficiency: This is an inherited disorder. It changes the way the body processes homocysteine. People who have this disorder should not take methionine supplements because methionine might cause homocysteine to build up in these people. Too much homocysteine might increase the chance of developing diseases of the heart or blood vessels.
Schizophrenia: Large doses of methionine (e.g., 20 g/day for 5 days) might cause confusion, disorientation, delirium, agitation, listlessness, and other similar symptoms in people with schizophrenia.
There are no known interactions with medications. Before taking this product, talk with your health professional if you take any medications.
There are no known interactions with herbs and supplements.
Salt and nitrite: Some research suggests that a diet rich in methionine, salt, and nitrite might increase the chance of getting stomach cancer.
The following doses have been studied in scientific research:
- For acetaminophen (Tylenol) poisoning: 2.5 grams of methionine every 4 hours for 4 doses.
DL-Methionine, DL Methionine, DL-Méthionine, L-2-amino-4-(methylthio)butyric acid, L-Methionine, L-Méthionine, Méthionine, Metionina.
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