Methionine is a protein that the body needs to function. It is found in meat, fish, and dairy. Methionine has been used to prevent urinary tract infections and protect the liver. It can be taken as a pill or powder. It can also be injected into the bloodstream by a healthcare provider.


There are no advised doses for methionine.

What Research Shows

Not Enough Data to Assess

  • Acetaminophen overdose A1
  • Chronic pancreatitis B1
  • HIVC1

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe for most adults to take methionine in small doses for a short time. Large doses may not be safe. Not enough studies have been done to say whether it is safe to take for a long period. Women who are pregnant or breastfeeding should limit their intake of methionine to food sources.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse.


A. Acetaminophen Overdose

A1. Chiew AL, Gluud C, et al. Interventions for paracetamol (acetaminophen) overdose. Cochrane Database Syst Rev. 2018;2:CD003328.

B. Chronic Pancreatitis

B1. Cai GH, Huang J, et al. Antioxidant therapy for pain relief in patients with chronic pancreatitis: systematic review and meta-analysis. Pain Physician. 2013;16(6):521-532.


C1. Van Brummelen R, du Toit D. L-methionine as immune supportive supplement: a clinical evaluation. 2007;33(1):157-163.

D. Safety

D1. Cottington EM, LaMantia C, et al. Adverse event associated with methionine loading test: a case report. Arterioscler Thromb Vasc Biol. 2002 Jun 1;22(6):1046-1050.

Last reviewed March 2020 by EBSCO NAT Review Board Eric Hurwitz, DC
Last Updated: 6/29/2020

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