- What other names is Methionine known by?
- What is Methionine?
- How does Methionine work?
- Are there safety concerns?
- Dosing considerations for Methionine.
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.
Possibly Effective for...
- Acetaminophen (Tylenol) poisoning. Research shows that receiving methionine by mouth or intravenously (by IV) seems to be effective for treating acetaminophen poisoning. Treatment should begin as quickly as possible, but must start within 10 hours of acetaminophen overdose.
Insufficient Evidence to Rate Effectiveness for...
- Cobalamin deficiency. Long-term exposure to nitrous oxide, which is given for anesthesia during surgery, might cause side effects that resemble cobalamin deficiency. Some research suggests that taking methionine by mouth before surgery might reduce these side effects of nitrous oxide.
- Colon cancer. Eating a diet that rich in methionine and folate (a type of B vitamin) seems to help reduce the risk of colon cancer. This seems to be especially true for people with a family history of colon cancer and people who drink large amounts of alcohol.
- Neural tube birth defects. Women who consume more dietary methionine during pregnancy seem to have a lower risk of neural tube birth defects.
- Parkinson's disease. Early research suggests that taking L-methionine by mouth for up to 6 months improves symptoms of Parkinson's disease, such as tremor, inability to control movements, and rigidity.
- Liver function.
- Radiation side effects.
- Drug withdrawal.
- Other conditions.
In acetaminophen poisoning, methionine prevents the breakdown products of acetaminophen from damaging the liver.
Methionine is POSSIBLY SAFE when taken by mouth or injected intravenously (by IV) to treat acetaminophen poisoning, but only under the supervision of a healthcare professional.
Don't treat yourself with methionine. It is POSSIBLY UNSAFE to self-medicate with methionine 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:Children: Methionine is POSSIBLY SAFE for children when given by mouth or injected intravenously (by IV) to treat acetaminophen poisoning, but only under the supervision of a healthcare professional. Methionine is POSSIBLY UNSAFE when injected intravenously into infants that are receiving parenteral nutrition.
“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.
The following doses have been studied in scientific research:
- 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.
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).
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Adams, J. M. and Capecchi, M. R. N-formylmethionyl-sRNA as the initiator of protein synthesis. Proc.Natl.Acad.Sci U.S.A 1966;55(1):147-155. View abstract.
CATONI, G. L. S-Adenosylmethionine; a new intermediate formed enzymatically from L-methionine and adenosinetriphosphate. J Biol.Chem. 1953;204(1):403-416. View abstract.
Cellarier, E., Durando, X., Vasson, M. P., Farges, M. C., Demiden, A., Maurizis, J. C., Madelmont, J. C., and Chollet, P. Methionine dependency and cancer treatment. Cancer Treat.Rev. 2003;29(6):489-499. View abstract.
Clark, B. F. and Marcker, K. A. How proteins start. Sci Am. 1968;218(1):36-42. View abstract.
Coelho CND, Klein NW. Methionine and neural tube closure in cultured rat embryos: morphological and biochemical analyses. Teratology 1990;42:437-451.
Di Buono, M., Wykes, L. J., Ball, R. O., and Pencharz, P. B. Dietary cysteine reduces the methionine requirement in men. Am.J.Clin.Nutr. 2001;74(6):761-766. View abstract.
Douglas, A. P., Hamlyn, A. N., and James, O. Controlled trial of cysteamine in treatment of acute paracetamol (acetaminophen) poisoning. Lancet 1-17-1976;1(7951):111-115. View abstract.
Essien FB and Wannaberg SL. Methionine but not folinic acid or vitamin B-12 alters the frequency of neural tube defects in Axd mutant mice. J Nutr 1993;123:27-34.
Finkelstein, J. D. Homocysteine: a history in progress. Nutr Rev 2000;58(7):193-204. View abstract.
Hamlyn, A. N., Lesna, M., Record, C. O., Smith, P. A., Watson, A. J., Meredith, T., Volans, G. N., and Crome, P. Methionine and cysteamine in paracetamol (acetaminophen) overdose, prospective controlled trial of early therapy. J.Int.Med.Res. 1981;9(3):226-231. View abstract.
Hanratty, C. G., McGrath, L. T., McAuley, D. F., Young, I. S., and Johnston, G. D. The effects of oral methionine and homocysteine on endothelial function. Heart 2001;85(3):326-330. View abstract.
Kurpad, A. V., Regan, M. M., Varalakshmi, S., Vasudevan, J., Gnanou, J., Raj, T., and Young, V. R. Daily methionine requirements of healthy Indian men, measured by a 24-h indicator amino acid oxidation and balance technique. Am.J.Clin.Nutr. 2003;77(5):1198-1205. View abstract.
L-methionine and naltrexone for insomnia. Posit.Health News 1998;(No 17):19. View abstract.
Larsson, S. C., Giovannucci, E., and Wolk, A. Methionine and vitamin B6 intake and risk of pancreatic cancer: a prospective study of Swedish women and men. Gastroenterology 2007;132(1):113-118. View abstract.
Lu, S., Hoestje, S. M., Choo, E. M., and Epner, D. E. Methionine restriction induces apoptosis of prostate cancer cells via the c-Jun N-terminal kinase-mediated signaling pathway. Cancer Lett. 5-8-2002;179(1):51-58. View abstract.
McAuley, D. F., Hanratty, C. G., McGurk, C., Nugent, A. G., and Johnston, G. D. Effect of methionine supplementation on endothelial function, plasma homocysteine, and lipid peroxidation. J.Toxicol.Clin.Toxicol. 1999;37(4):435-440. View abstract.
McGowan, K. A., Nyhan, W. L., Barshop, B. A., Naviaux, R. K., Yu, A., Haas, R. H., and Townsend, J. J. The role of methionine in ethylmalonic encephalopathy with petechiae. Arch.Neurol. 2004;61(4):570-574. View abstract.
Meininger, V., Flamier, A., Phan, T., Ferris, O., Uzan, A., and Lefur, G. [L-Methionine treatment of Parkinson's disease: preliminary results]. Rev.Neurol.(Paris) 1982;138(4):297-303. View abstract.
Moss, R. L., Haynes, A. L., Pastuszyn, A., and Glew, R. H. Methionine infusion reproduces liver injury of parenteral nutrition cholestasis. Pediatr.Res. 1999;45(5 Pt 1):664-668. View abstract.
Sasamura, T., Matsuda, A., and Kokuba, Y. Effects of D-methionine-containing solution on tumor cell growth in vitro. Arzneimittelforschung. 1999;49(6):541-543. View abstract.
Shaw, G. M., Velie, E. M., and Schaffer, D. M. Is dietary intake of methionine associated with a reduction in risk for neural tube defect-affected pregnancies? Teratology 1997;56(5):295-299. View abstract.
Shoob, H. D., Sargent, R. G., Thompson, S. J., Best, R. G., Drane, J. W., and Tocharoen, A. Dietary methionine is involved in the etiology of neural tube defect-affected pregnancies in humans. J.Nutr. 2001;131(10):2653-2658. View abstract.
Smulders, Y. M., Rakic, M., Slaats, E. H., Treskes, M., Sijbrands, E. J., Odekerken, D. A., Stehouwer, C. D., and Silberbusch, J. Fasting and post-methionine homocysteine levels in NIDDM. Determinants and correlations with retinopathy, albuminuria, and cardiovascular disease. Diabetes Care 1999;22(1):125-132. View abstract.
TABOR, H., ROSENTHAL, S. M., and TABOR, C. W. The biosynthesis of spermidine and spermine from putrescine and methionine. J Biol.Chem. 1958;233(4):907-914. View abstract.
Tan, Y., Zavala, J., Sr., Xu, M., Zavala, J., Jr., and Hoffman, R. M. Serum methionine depletion without side effects by methioninase in metastatic breast cancer patients. Anticancer Res. 1996;16(6C):3937-3942. View abstract.
Trumbo, P., Schlicker, S., Yates, A. A., and Poos, M. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids. J Am.Diet.Assoc. 2002;102(11):1621-1630. View abstract.
Ward, M., McNulty, H., McPartlin, J., Strain, J. J., Weir, D. G., and Scott, J. M. Effect of supplemental methionine on plasma homocysteine concentrations in healthy men: a preliminary study. Int.J.Vitam.Nutr.Res. 2001;71(1):82-86. View abstract.
Yaghmai, R., Kashani, A. H., Geraghty, M. T., Okoh, J., Pomper, M., Tangerman, A., Wagner, C., Stabler, S. P., Allen, R. H., Mudd, S. H., and Braverman, N. Progressive cerebral edema associated with high methionine levels and betaine therapy in a patient with cystathionine beta-synthase (CBS) deficiency. Am.J.Med.Genet. 2-15-2002;108(1):57-63. View abstract.
Anon. Should methionine be added to paracetamol formulations? Drug Ther Perspect 1997;10:11-3.
Barshop BA. Homocystiniuria. In: Goldman L, Bennett JC. Cecil Textbook of Medicine. 21st ed. Philadelphia, PA: W.B. Saunders Co. 2000:1115-6.
Bellamy MF, McDowell IF, Ramsey MW, et al. Hyperhomocysteinemia after an oral methionine load acutely impairs endothelial function in healthy adults. Circulation 1998;98:1848-52. View abstract.
Bellone J, Farello G, Bartolotta E, et al. Methionine potentiates both basal and GHRH-induced GH secretion in children. Clin Endocrinol (Oxf) 1997;47:61-4. View abstract.
Btaiche IF, Khalidi N. Parenteral nutrition-associated liver complications in children. Pharmacotherapy 2002;22:188-211.. View abstract.
Christensen B, Guttormsen AB, Schneede J, et al. Preoperative methionine loading enhances restoration of the cobalamin-dependent enzyme methionine synthase after nitrous oxide anesthesia. Anesthesiology 1994;80:1046-56. View abstract.
Cottington EM, LaMantia C, Stabler SP, et al. Adverse event associated with methionine loading test: a case report. Arterioscler Thromb Vasc Biol 2002;22:1046-50.. View abstract.
Epner DE, Morrow S, Wilcox M, Houghton JL. Nutrient intake and nutritional indexes in adults with metastatic cancer on a phase I clinical trial of dietary methionine restriction. Nutr Cancer 2002;42:158-66.. View abstract.
Epner DE. Can dietary methionine restriction increase the effectiveness of chemotherapy in treatment of advanced cancer? J Am Coll Nutr 2001;20:443S-9S.. View abstract.
Frosst P, Blom HJ, Milos R, et al. A candidate genetic risk factor for vascular disease: a common mutation in methylenetetrahydrofolate reductase. Nat Genet 1995;10:111-3.. View abstract.
Fuchs CS, Willett WC, Colditz GA, et al. The influence of folate and multivitamin use on the familial risk of colon cancer in women. Cancer Epidemiol Biomarkers Prev 2002;11:227-34.. View abstract.
Girelli D, Martinelli N, Pizzolo F, et al. The interaction between MTHFR 677 C-->T genotype and folate status is a determinant of coronary atherosclerosis risk. J Nutr 2003;133:1281-5. View abstract.
Hladovec J, Sommerova Z, Pisarikova A. Homocysteinemia and endothelial damage after methionine load. Thromb Res 1997;88:361-4. View abstract.
Kokko JP. Fluids and electrolytes. In: Goldman L, Bennett JC. Cecil Textbook of Medicine. 21st ed. Philadelphia, PA: W.B. Saunders Co. 2000:59.
La Vecchia C, Negri E, Franceschi S, Decarli A. Case-control study on influence of methionine, nitrite, and salt on gastric carcinogenesis in northern Italy. Nutr Cancer 1997;27:65-8. View abstract.
Meakins TS, Persaud C, Jackson AA. Dietary supplementation with L-methionine impairs the utilization of urea-nitrogen and increases 5-L-oxoprolinuria in normal women consuming a low protein diet. J Nutr 1998;128:720-7. View abstract.
Russman S, Junker E, Lauterburg BH. Remethylation and transsulfuration of methionine in cirrhosis: studies with L-[H3-methyl-1-C]methionine. Hepatology 2002;36:1190-6.. View abstract.
Su LJ, Arab L. Nutritional status of folate and colon cancer risk: evidence from NHANES I epidemiologic follow-up study. Ann Epidemiol 2001;11:65-72.. View abstract.
Vale JA, Meredith TJ, Goulding R. Treatment of acetaminophen poisoning. The use of oral methionine. Arch Intern Med 1981;141:394-6. View abstract.
Ward M, McNulty H, Pentieva K, et al. Fluctuations in dietary methionine intake do not alter plasma homocysteine concentrations in healthy men. J Nutr 2000;130:2653-7.. View abstract.