What Is It?
Health Benefits

Dosage Information

Guidelines for Use

General Interaction
Possible Side Effects
Evidence Based Rating Scale

What Is It?

The importance of adequate stores of the amino acid methionine cannot be underestimated. Methionine is an essential amino acid –one that must come from external sources because the body cannot produce it. It is particularly important because it supplies sulfur--a Mineral--that helps to maintain healthy skin tone, well-conditioned hair, and strong nails. It also is responsible for creating two essential molecules: choline and creatine. Choline is important for cognitive function, and creatine produces energy that helps to build up muscles. Because the body can't produce this essential amino acid on its own, methionine-rich foods like cheddar cheese, eggs, chicken, and beef are important sources. Supplements are also available. 

Methionine goes through several changes during metabolism. In the methionine cycle, the amino acid is first transformed into S-adenosylmethionine (SAMe), a molecule that then donates a piece of itself (a methyl group) to body tissues and organs, providing a critical link in methylation, a chemical reaction that occurs billions of times a day throughout the body. In giving up a part of itself, SAMe promotes cell growth and repair. (SAMe is also available as a supplement that supports other functions. For more information, see the WholeHealthMD article on SAMe.) After donating its methyl group, SAMe is hydrolyzed to homocysteine, and then either remethylated to methionine or transsulfurated in a process that leads to the formation of cysteine, taurine, and glutathione. Maintaining stability of this methionine cycle is believed to help prevent damage to the liver as well as preventing build-up of homocysteine. (1, 2) 

Methionine is thought to keep Fat from building up in the liver, and it is often included in liver-detoxifying products called lipotropic combinations. These formulations are believed to accelerate the flow of bile and cell-damaging toxins away from the liver. They commonly contain the B vitamins choline and inositol in addition to methionine. 

Health Benefits 

The liver-detoxifying effects of methionine account for many of the beneficial uses of the amino acid, such as to remove fat from the liver, to reverse and prevent the formation of gallstones in the gallbladder, and to treat endometriosis by processing excess estrogen in the liver. 

Specifically, methionine may help to: 

Treat endometriosis. Methionine in lipotropic combinations has been proposed for treating endometriosis, a condition in which patches of tissue like that in the lining of the uterus (endometrium) grow outside the uterus. (3) The nutrient is believed to help by expediting the removal of excess estrogen from the liver. The bleeding, cramps, pain, and other complications of this common ailment may subside as a result. More research is needed, however. 

Prevent gallstones. By interacting with the metabolism of fat in the liver to speed its removal, methionine may be useful in preventing gallstones. These pebble-like substances form in the gallbladder, which stores bile until it is needed to digest fat in the foods we eat. Some early animal studies have shown that not only does a six-week methionine-deficient diet in canines lead to the formation of pigment gallstones, but return to a normal diet may actually lead to the reversal of stone formation suggesting a preventative effect of a methionine-rich diet. These studies showed that after returning to a methionine-rich diet, existing gallstones in dogs dissolved, and bile flow improved. (4-7) However, studies are needed to determine efficacy in humans. 

Remove toxins in Candida overgrowth syndrome. Lipotropic supplements that contain methionine are often recommended by naturopathic physicians to treat Candida overgrowth syndrome (COS), which occurs when the yeast Candida albicans (commonly known as Candida) excessively populates one or more locations in the body. When this happens, Candida-related toxins suppress the liver's normal function, leading to multiple chemical sensitivities and allergies associated with COS. Lipotropic combinations including choline, betaine, methionine, and silymarin (milk thistle) may help to enhance liver function and protect the liver from toxic substances associated with COS. (8-10) However, research is limited. Methionine alone in has not been evaluated in treatment of COS. 

Prevent and treat sports injuries. The role of methionine in the manufacture of creatine may help to build and repair muscles, as well as ease pain in the joints. Some evidence indicates that the microscopic muscle tears that occur during sports injuries heal more quickly in the presence of creatine, and, because creatine produces short bursts of energy, it enhances muscle performance during repeated bouts of brief, high-intensity exercise. (11-12) Other studies indicate that individuals who take L-carnitine, a supplement containing methionine, while exercising are less likely to experience muscle soreness. (13-15) However, methionine has not been studied directly for this use. Research is needed.

Treat liver toxicity. In humans, methionine given within the first ten hours after acetaminophen overdose has been shown to reduce liver damage and prevent death. (17) In research with animals, it also appears to reduce liver injury from alcohol, lead, and other liver toxins. (18) 


  • Capsule
  • Powder
  • Tablet 

Dosage Information

The recommended intake for methionine is 13 mg daily for every kg of weight (about 1 g daily for adults).

Doses up to 250 mg daily are generally well tolerated. 

Guidelines for Use

Take methionine with meals to avoid stomach upset. 

General Interaction

There are no known drug interactions associated with methionine.

A diet rich in methionine, salt and nitrite might increase the risk of gastric cancer. 

Possible Side Effects

Large amounts of methionine (doses higher than 250 mg daily) may cause nausea, vomiting, and headaches. 


Avoid taking more than the commonly recommended amount of methionine. This is particularly important if the diet is low in folic acid, Vitamin B6, or vitamin B12, because this could increase the conversion of methionine to Homocysteine 

A strong correlation has been found between high plasma levels of homocysteine that are produced during the metabolism of methionine and the risk of cognitive impairment in diseases such as Alzheimer's Disease, age-related memory loss, and dementia as well as cardiovascular disease. Folate and vitamin B12 are needed in the conversion of homocysteine back to methionine; thus homocysteine can become high when deficiencies of these other nutrients are present. Providing these nutritional cofactors for proper functioning of the methionine cycle may help to protect the brain from damage. (16)  

If you have any serious illness or are pregnant, only take an amino acid such as methionine after consulting your doctor.

To be safe, never take methionine--or any single amino acid for that matter--for longer than three months unless you are under the direction of a doctor familiar with its use. 


1. Russman S, Junker E, Lauterburg BH. Remethylation and transsulfuration of methionine in cirrhosis: studies with L-[H3-methyl-1-Cjmethionine. Hepatology. 2002;36:1190-6.
2. Btaiche IF, Khalidi N. Parenteral nutrition-associated liver complications in children. Pharmacotherapy. 2002;22:188-211.
3. Null G. The Complete Encyclopedia of Natural Healing. 2nd ed. New York, New York: Kensington Publishing Company; 2005:235.
4. Dawes LG, Nahrwold DL, Rege RV. Increased total and free ionized calcium in a canine model of pigment gallstones. Surgery 1988 Jul;104(1):86-90.
5. Dawes LG, Nahrwold DL, Rege RV. Supersaturation of canine gallbladder bile with calcium bilirubinate during formation of pigment gallstones. Am J Surg. 1989 Jan;157(1):82-8.4. Dawes LG, Nahrwold DL, Roth SI, Rege RV. Reversal of pigment gallstone disease in a canine model. Arch Surg. 1989 Apr;124(4):463-6.
6. Christian JS, Rege RV. Methionine, but not taurine, protects against formation of canine pigment gallstones. Surg Res. 1996 Feb 15;61(1):275-81.
7. Boari C, Montanari FM, Galletti GP, et al. Toxic occupational liver diseases. Therapeutic effects of silymarin.  Minerva Med. 1981;72:2679-2688.
8. Salmi HA, Sarna S. Effect of silymarin on chemical, functional, and morphological alteration of the liver. A double-blind, controlled study. Scand J Gastroenterol. 1982;17:517-521.
9. Ferenci P, Dragosics B, Dittrich H, et al. Randomized, controlled trial of silymarin treatment in patients with cirrhosis of the liver. J Hepatol 1989;9:105-113.
10. Kerksick CM, Wilborn CD, Campbell WI, Harvey TM, Marcello BM, Roberts MD, Parker AG, Byars AG, Greenwood LD, Almada AL, Kreider RB, Greenwood M. The effects of creatine monohydrate supplementation with and without D-pinitol on resistance training adaptations. J Strength Cond Res. 2009 Dec;23(9):2673-82.
11. Vandenberghe K, Goris M, Van Hecke P, Van Leemputte M, Vangerven L, Hespel P. Long-term creatine intake is beneficial to muscle performance during resistance training. J Appl Physiol. 1997 Dec;83(6):2055-63.
12. Giamberardino MA, Dragani L, Valente R, et al. Effects of prolonged L-carnitine administration on delayed muscle pain and CK release after eccentric effort. Int J Sports Med. 1996 Jul;17(5):320-4.
13. Spiering BA, Kraemer WJ, Vingren JL, et al. Responses of criterion variables to different supplemental doses of L-carnitine L-tartrate. J Strength Cond Res. 2007 Feb;21(1):259-64.
14. Ho JY, Kraemer WJ, Volek JS, et al. L-Carnitine l-tartrate supplementation favorably affects biochemical markers of recovery from physical exertion in middle-aged men and women. Metabolism. 2010 Aug;59(8):1190-9.
15. Miller AL. The methionine-homocysteine cycle and its effects on cognitive diseases. Altern Med Rev. 2003 Feb;8(1):7-19.
16. Zhuo JM, Pratico D. Normalization of hyperhomocysteinemia improves cognitive deficits and ameliorates brain amyloidosis of a transgenic mouse model of Alzheimer's disease. FASEB J. 2010 Oct;24(10):3895-902.
17. Wright B, Crowe M. Use of oral methionine for overdose below threshold for acetylcysteine. BMJ 1998;317:1656.
18. Friedel HA, Goa KL, Benfield P. S-adenosyl-i-methionine: a review of its pharmacological properties and therapeutic potential in liver dysfunction and affective disorders in relation to its physiological role in cell metabolism. Drugs, 1989;38:389-416.

Evidence Based Rating Scale

The Evidence Based Rating Scale is a tool that helps consumers translate the findings of medical research studies and what our clinical advisors have found to be efficacious in their personal practice into a visual and easy to interpret format. This tool is meant to simplify the information on supplements and therapies that demonstrate promise in the treatment of certain conditions.




Candida overgrowth syndrome


Preliminary evidence indicates potential benefit. More research is needed. (8-10)

Preliminary evidence indicates potential efficacy in lipotropic combinations. More research is needed. (3)

Several preliminary studies in animals indicate efficacy to prevent and treat gallstones. Human studies are needed. (4-7)

Sports injuries
Studies indicate efficacy of creatine (a derivative of methionine) and L-carnitine (a supplement containing methionine) in speeding wound healing and reducing muscle soreness, but methionine has not been studied directly for these uses. Research is needed. (11-15)





Date Published: 04/19/2005
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