Reviewed on 6/11/2021
Other Name(s):

1-carboxy-2-[2-mercaptoimidazole-4-(or 5)-yl]ethyl]-trimethyl-ammonium hydroxide, 2-Mercaptohistidine Trimethylbetaine, Ergothionéine, Ergotioneina, Erythrothioneine, ET, L-Ergo, L-Ergothioneine, S-alpha-carboxy-2,3-dihydro-N,N-N,-trimethyl-thioxo-1H-imidazole-4-eth-anaminium hydroxide, Sympectothion, Thiasine, Thiazine, Thiolhistidinebetaine, Thioneine, Thionéine, Thiozine.


Ergothioneine is an amino acid that is found mainly in mushrooms, but also in king crab, meat from animals that have grazed on grasses containing ergothioneine, and other foods. Amino acids are chemicals that are the building blocks for proteins. Ergothioneine is used as medicine.

People take ergothioneine for liver damage, cataracts, Alzheimer's disease, diabetes, and heart disease.

Ergothioneine is sometimes applied directly to the skin to prevent wrinkles, reduce signs of aging skin, and reduce sun damage.

How does it work?

Researchers are investigating ergothioneine to determine if it can reduce swelling (inflammation) in the lungs and damage in the liver, kidneys, and brain.


Next to red peppers, you can get the most vitamin C from ________________. See Answer

Uses & Effectiveness

Insufficient Evidence to Rate Effectiveness for...

  • Liver damage.
  • Cataracts.
  • Alzheimer's disease.
  • Diabetes.
  • Heart disease.
  • Preventing wrinkles and reducing signs of aging, when applied to the skin.
  • Other conditions.
More evidence is needed to rate the effectiveness of ergothioneine for these uses.

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).

Side Effects

Ergothioneine is LIKELY SAFE when used in amounts found in foods. But there isn’t enough information to know if ergothioneine is safe when taken as a supplement for medical purposes.


Vitamin D Deficiency: How Much Vitamin D Is Enough? See Slideshow

Special Precautions & Warnings

Pregnancy and breast-feeding: Not enough is known about the use of ergothioneine during pregnancy and breast-feeding. Stay on the safe side and avoid use.


The appropriate dose of ergothioneine depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for ergothioneine. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Health Solutions From Our Sponsors


Akanmu, D., Cecchini, R., Aruoma, O. I., and Halliwell, B. The antioxidant action of ergothioneine. Arch Biochem Biophys 1991;288(1):10-16. View abstract.

Arduini, A., Mancinelli, G., Radatti, G. L., Hochstein, P., and Cadenas, E. Possible mechanism of inhibition of nitrite-induced oxidation of oxyhemoglobin by ergothioneine and uric acid. Arch Biochem Biophys 5-1-1992;294(2):398-402. View abstract.

Aruoma, O. I., Spencer, J. P., and Mahmood, N. Protection against oxidative damage and cell death by the natural antioxidant ergothioneine. Food Chem Toxicol. 1999;37(11):1043-1053. View abstract.

Boldyrev, A. and Abe, H. Metabolic transformation of neuropeptide carnosine modifies its biological activity. Cell Mol.Neurobiol. 1999;19(1):163-175. View abstract.

Botta, C., Di, Giorgio C., Sabatier, A. S., and De, Meo M. Genotoxicity of visible light (400-800 nm) and photoprotection assessment of ectoin, L-ergothioneine and mannitol and four sunscreens. J Photochem.Photobiol.B 4-25-2008;91(1):24-34. View abstract.

Brummel, M. C. In search of a physiological function for L-ergothioneine--II. Med Hypotheses 1989;30(1):39-48. View abstract.

Brummel, M. C. In search of a physiological function for L-ergothioneine. Med Hypotheses 1985;18(4):351-370. View abstract.

Carlsson, J., Kierstan, M. P., and Brocklehurst, K. A convenient spectrophotometric assay for the determination of L-ergothioneine in blood. Biochem J 1974;139(1):237-242. View abstract.

Decome, L., De, Meo M., Geffard, A., Doucet, O., Dumenil, G., and Botta, A. Evaluation of photolyase (Photosome) repair activity in human keratinocytes after a single dose of ultraviolet B irradiation using the comet assay. J Photochem.Photobiol.B 5-13-2005;79(2):101-108. View abstract.

Dong, K. K., Damaghi, N., Kibitel, J., Canning, M. T., Smiles, K. A., and Yarosh, D. B. A comparison of the relative antioxidant potency of L-ergothioneine and idebenone. J Cosmet.Dermatol 2007;6(3):183-188. View abstract.

Epand, R. M. The role of dietary ergothioneine in the development of diabetes mellitus. Med Hypotheses 1982;9(2):207-213. View abstract.

Epand, R. M., Epand, R. F., and Wong, S. C. Study of the ergothioneine concentration in the blood of individuals with diabetes mellitus. J Clin Chem Clin Biochem 1988;26(10):623-626. View abstract.

Ey, J., Schomig, E., and Taubert, D. Dietary sources and antioxidant effects of ergothioneine. J Agric Food Chem 8-8-2007;55(16):6466-6474. View abstract.

Hand, C. E. and Honek, J. F. Biological chemistry of naturally occurring thiols of microbial and marine origin. J Nat Prod 2005;68(2):293-308. View abstract.

Hayeshi, R., Mukanganyama, S., Hazra, B., Abegaz, B., and Hasler, J. The interaction of selected natural products with human recombinant glutathione transferases. Phytother.Res 2004;18(11):877-883. View abstract.

Kato, Y., Kubo, Y., Iwata, D., Kato, S., Sudo, T., Sugiura, T., Kagaya, T., Wakayama, T., Hirayama, A., Sugimoto, M., Sugihara, K., Kaneko, S., Soga, T., Asano, M., Tomita, M., Matsui, T., Wada, M., and Tsuji, A. Gene knockout and metabolome analysis of carnitine/organic cation transporter OCTN1. Pharm Res 2010;27(5):832-840. View abstract.

Kerby, G. P. and Taylor, S. M. Effect of carnitine and ergothioneine on human platelet metabolism. Proc Soc Exp Biol Med 1969;132(2):435-439. View abstract.

Kuchel, P. W. and Chapman, B. E. Proton NMR studies of creatine in human erythrocytes. Biomed.Biochim.Acta 1983;42(9):1143-1149. View abstract.

Kumosani, T. A. L-ergothioneine level in red blood cells of healthy human males in the Western province of Saudi Arabia. Exp Mol Med 3-31-2001;33(1):20-22. View abstract.

Kuninori, T. and Nishiyama, J. Measurement of biological thiols and disulfides by high-performance liquid chromatography and electrochemical detection of silver mercaptide formation. Anal.Biochem 8-15-1991;197(1):19-24. View abstract.

Markova, N. G., Karaman-Jurukovska, N., Dong, K. K., Damaghi, N., Smiles, K. A., and Yarosh, D. B. Skin cells and tissue are capable of using L-ergothioneine as an integral component of their antioxidant defense system. Free Radic.Biol Med 4-15-2009;46(8):1168-1176. View abstract.

Menna, P., Salvatorelli, E., Giampietro, R., Liberi, G., Teodori, G., Calafiore, A. M., and Minotti, G. Doxorubicin-dependent reduction of ferrylmyoglobin and inhibition of lipid peroxidation: implications for cardiotoxicity of anticancer anthracyclines. Chem Res Toxicol. 2002;15(9):1179-1189. View abstract.

Obayashi, K., Kurihara, K., Okano, Y., Masaki, H., and Yarosh, D. B. L-Ergothioneine scavenges superoxide and singlet oxygen and suppresses TNF-alpha and MMP-1 expression in UV-irradiated human dermal fibroblasts. J Cosmet.Sci 2005;56(1):17-27. View abstract.

Rabenstein, D. L. and Isab, A. A. A proton nuclear magnetic resonance study of the interaction of mercury with intact human erythrocytes. Biochim.Biophys Acta 12-30-1982;721(4):374-384. View abstract.

Reglinski, J., Hoey, S., Smith, W. E., and Sturrock, R. D. Cellular response to oxidative stress at sulfhydryl group receptor sites on the erythrocyte membrane. J Biol Chem 9-5-1988;263(25):12360-12366. View abstract.

Reglinski, J., Smith, W. E., and Sturrock, R. D. Spin-echo 1H NMR detected response of ergothioneine to oxidative stress in the intact human erythrocyte. Magn Reson.Med 1988;6(2):217-223. View abstract.

Reglinski, J., Smith, W. E., Wilson, R., Buchanan, L. M., McKillop, J. H., Thomson, J. A., Brzeski, M., Marabani, M., and Sturrock, R. D. Clinical analysis in intact erythrocytes using 1H spin echo NMR. Clin Chim.Acta 9-14-1991;201(1-2):45-57. View abstract.

Sawiniec, Z. and Szumilo, T. [Determination of ergothioneine in human blood cells]. Pol Tyg.Lek. 8-21-1967;22(34):1293-1295. View abstract.

Shukla, Y., Kulshrestha, O. P., and Khuteta, K. P. Ergothioneine content in normal and senile human cataractous lenses. Indian J Med Res 1981;73:472-473. View abstract.

Smiles, K. A., Dong, K. K., Canning, M. T., Grimson, R., Walfield, A. M., and Yarosh, D. B. A hydroquinone formulation with increased stability and decreased potential for irritation. J Cosmet.Dermatol 2007;6(2):83-88. View abstract.

Taubert, D., Jung, N., Goeser, T., and Schomig, E. Increased ergothioneine tissue concentrations in carriers of the Crohn's disease risk-associated 503F variant of the organic cation transporter OCTN1. Gut 2009;58(2):312-314. View abstract.

Taubert, D., Lazar, A., Grimberg, G., Jung, N., Rubbert, A., Delank, K. S., Perniok, A., Erdmann, E., and Schomig, E. Association of rheumatoid arthritis with ergothioneine levels in red blood cells: a case control study. J Rheumatol 2006;33(11):2139-2145. View abstract.

Urban, T. J., Yang, C., Lagpacan, L. L., Brown, C., Castro, R. A., Taylor, T. R., Huang, C. C., Stryke, D., Johns, S. J., Kawamoto, M., Carlson, E. J., Ferrin, T. E., Burchard, E. G., and Giacomini, K. M. Functional effects of protein sequence polymorphisms in the organic cation/ergothioneine transporter OCTN1 (SLC22A4). Pharmacogenet.Genomics 2007;17(9):773-782. View abstract.

van den Broeke, L. T. and Beyersbergen van Henegouwen, G. M. Thiols as potential UV radiation protectors: an in vitro study. J Photochem.Photobiol.B 1993;17(3):279-286. View abstract.

Vetrella, M., Barthelmai, W., Risolo, E., and Vetrella, A. [Ergothioneine and reduced ergothioneine/glutathione (GSH) ratio in erythrocytes of patients with cystinosis and in heterozygotes]. Pediatria.(Napoli) 9-30-1978;86(3):421-426. View abstract.

Xiao, L., Zhao, L., Li, T., Hartle, D. K., Aruoma, O. I., and Taylor, E. W. Activity of the dietary antioxidant ergothioneine in a virus gene-based assay for inhibitors of HIV transcription. Biofactors 2006;27(1-4):157-165. View abstract.

Cargnoni A, Bernocchi P, Ceconi C, et al. In vitro administration of ergothioneine failed to protect isolated ischaemic and reperfused rabbit heart. Biochim Biophys Acta 1995;1270:173-8. View abstract.

Deiana M, Rosa A, Casu V, et al. L-ergothioneine modulates oxidative damage in the kidney and liver of rats in vivo: studies upon the profile of polyunsaturated fatty acids. Clin Nutr 2004;23:183-93. View abstract.

Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at:

Franzoni F, Colognato R, Galetta F, et al. An in vitro study on the free radical scavenging capacity of ergothioneine: comparison with reduced glutathione, uric acid and trolox. Biomed Pharmacother 2006;60:453-7. View abstract.

Grundemann D, Harlfinger S, Golz S, et al. Discovery of the ergothioneine transporter. Proc Natl Acad Sci U S A 2005;102:5256-61. View abstract.

Guijarro MV, Indart A, Aruoma OI, et al. Effects of ergothioneine on diabetic embryopathy in pregnant rats. Food Chem Toxicol 2002;40:1751-5. View abstract.

Jang JH, Aruoma OI, Jen LS, et al. Ergothioneine rescues PC12 cells from beta-amyloid-induced apoptotic death. Free Radic Biol Med 2004;36:288-99. View abstract.

Mitsuyama H, May JM. Uptake and antioxidant effects of ergothioneine in human erythrocytes. Clin Sci (Lond) 1999;97:407-11. View abstract.

Moncaster JA, Walsh DT, Gentleman SM, et al. Ergothioneine treatment protects neurons against N-methyl-D-aspartate excitotoxicity in an in vivo rat retinal model. Neurosci Lett 2002;328:55-9. View abstract.

Rahman I, Gilmour PS, Jimenez LA, et al. Ergothioneine inhibits oxidative stress- and TNF-alpha-induced NF-kappa B activation and interleukin-8 release in alveolar epithelial cells. Biochem Biophys Res Commun 2003;302:860-4. View abstract.

Sakrak O, Kerem M, Bedirli A, et al. Ergothioneine modulates proinflammatory cytokines and heat shock protein 70 in mesenteric ischemia and reperfusion injury. J Surg Res 2008;144:36-42. View abstract.

Health Solutions From Our Sponsors