METHIONINE Overview Information
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, and it plays an important role in many cell functions.
Methionine is used to prevent liver damage in acetaminophen (Tylenol) poisoning. It is also used for increasing the acidity of urine, treating liver disorders, and improving wound healing. Other uses include treating depression, alcoholism, allergies, asthma, copper poisoning, radiation side effects, schizophrenia, drug withdrawal, and Parkinson's disease.
How does it work?
In acetaminophen poisoning, methionine prevents the breakdown products of acetaminophen from damaging the liver.
METHIONINE Uses & Effectiveness 
Possibly Effective for:
- Preventing liver damage in cases of acetaminophen (Tylenol) poisoning when given by mouth or intravenously (by IV) by emergency room staff. Treatment should begin as quickly as possible, but must start within 10 hours of acetaminophen overdose.
Insufficient Evidence for:
- Colon cancer. There is some evidence that eating a diet that is rich in methionine and folate (a type of B vitamin) might help to prevent coloncancer, especially in people with a family history of colon cancer and in people who drink large amounts of alcohol.
- Maintaining normal liver function.
- Treating depression.
- Alcoholism.
- Allergies.
- Asthma.
- Radiation side effects.
- Schizophrenia.
- Drug withdrawal.
- Parkinson's disease.
- Other conditions.
METHIONINE Side Effects & Safety
Methionine seems to be safe for treating acetaminophen poisoning, but only under the supervision of a healthcare professional.
Don’t treat yourself with methionine. It may be UNSAFE to use methionine to self-medicate if you use larger amounts than those typically found in food. Too much methionine can cause brain damage and death. Methionine can increase blood levels of homocysteine, a chemical that might cause heart disease. Methionine might also promote the growth of some tumors.
Special Precautions & Warnings:
Pregnancy and breast-feeding: Not enough is known about the use of methionine during pregnancy and breast-feeding. 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.
METHIONINE Interactions
We currently have no information for METHIONINE Interactions
METHIONINE Dosing
The following doses have been studied in scientific research:
BY MOUTH:
- For acetaminophen (Tylenol) poisoning: 2.5 grams of methionine every 4 hours for 4 doses to prevent liver damage and death. Methionine must be given within 10 hours of taking the acetaminophen. This should be done by a healthcare professional.
