Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.
Methionine is an antioxidant and is thought to help protect the body from damage caused by ionizing radiation, detoxify harmful substances in the body (particularly heavy metals) and inhibit fat deposition in the liver.
In addition, methionine may help alleviate fatigue and may be useful in lessening early balding and the effects of osteoporosis.
Amino acids (AAs) are available as individual AAs or in proprietary AA combinations, as well as part of multi-vitamin formulas, proteins and food supplements. The forms include tablets, fluids and powders. However, adequate protein in the diet should provide a sufficient source of all amino acids.
There are no conditions that increase the requirements for methionine.
Side Effects, Toxicity and Interactions:
The use of a single amino acid supplement may lead to a negative nitrogen balance, decreasing metabolic efficiency and increasing the workload in the kidneys. In children, taking single amino acid supplements may also harmfully affect growth parameters.
Always avoid taking individual amino acids in high dosage for prolonged periods.
Women who are pregnant or breast-feeding should not use methionine supplements.
Individuals with homocystinuria type I, an inherited disease, should not use methionine supplements.
Click here for a list of reputable Web sites with general information on nutrition.
Weast RC, Astle MJ, Beyer WH, eds. Handbook of Chemistry and Physics. 65th ed. Boca Raton, FL: CRC Press, Inc.; 1984.
Lide DR, Frederikse HPR, eds. Handbook of Chemistry and Physics. 75th ed. Boca Raton, FL: CRC Press, Inc.; 1994.
Murray RK, Granner DK, Mayes PA, Rodwell VW. Harper's Biochemistry. 25th ed. Stamford, CT: Appleton & Lange; 2000.
Meisenberg G, Simmons WH. Principles of Medical Biochemistry. Mosby Pub. Co.; 1998.
Styer L. Biochemistry. 4th ed. W.H. Freeman & Co.; 1995.
Montgomery R, Conway TW, Spector AA, Chappell D. Biochemistry: A Case-Oriented Approach. 6th ed. Mosby Pub. Co.; 1996.
Nelson WE, Behrman RE, Kliegman RM, Arvin AM, eds. Nelson Textbook of Pediatrics. 15th ed. Philadelphia: W.B. Saunders Company; 1996:335-338.