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Brewer’s Yeast


Brewer’s yeast is a by-product made when brewing beer. It has been used to aid digestion. It can be taken as a pill or powder.


500 milligrams 1 to 2 times daily.

What Research Shows

Likely Effective

May Be Effective

Not Enough Data to Assess

  • Premenstrual syndrome D1

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 brewer’s yeast for a short time. People sensitive or allergic to yeast may have reactions to brewer’s yeast. Not enough studies have been done to say whether it is safe to take for a long period. It is also not known whether it is safe to take by women who are pregnant or breastfeeding.


Talk to your doctor about any alternative therapy or supplements you are taking to make sure they do not interfere with your current treatment.

  • People with Crohn’s disease or weakened immune systems from other diseases or treatments should talk to their doctors before taking brewer’s yeast.E1, E2



A. Allergic Rhinitis

A1. Moyad MA, Robinson LE, et al. Immunogenic yeast-based fermentation product reduces allergic rhinitis-induced nasal congestion: a randomized, double-blind, placebo-controlled trial. Adv Ther. 2009 Aug;26(8):795-804.

B. Cold/Flu-Like Symptoms

B1. Moyad MA, Robinson LE, et al. Effects of a modified yeast supplement on cold/flu symptoms. Urol Nurs. 2008 Feb;28(1):50-55.

B2. Moyad MA, Robinson LE, et al. Immunogenic yeast-based fermentate for cold/flu-like symptoms in nonvaccinated individuals. J Altern Complement Med. 2010 Feb;16(2):213-218.

C. Irritable Bowel Syndrome

C1. Pineton de Chambrun G, Neut C, et al. A randomized clinical trial of Saccharomyces cerevisiae versus placebo in the irritable bowel syndrome. Dig Liver Dis. 2015;47(2):119-124.

C2. Cayzeele-Decherf A, Pélerin F, et al. Saccharomyces cerevisiae CNCM I-3856 in irritable bowel syndrome: An individual subject meta-analysis. World J Gastroenterol. 2017;23(2):336-344.

D. Premenstrual Syndrome

D1. Facchinetti F, Nappi RE, et al. Effects of a yeast-based dietary supplementation on premenstrual syndrome. A double-blind placebo-controlled study. Gynecol Obstet Invest. 1997;43(2):120-124.

E. Safety

E1. Alic M. Baker's yeast in Crohn's disease--can it kill you? Am J Gastroenterol. 1999 Jun;94(6):1711.

E2. Muñoz P, Bouza E, et al. Saccharomyces cerevisiae fungemia: an emerging infectious disease. Clin Infect Dis. 2005 Jun 1;40(11):1625-1634.

Last reviewed August 2019 by EBSCO CAM Review Board  Last Updated: 2/18/2020