Overview

Brewer’s yeast is a common strain of yeast found in nutritional supplements. It is available as a dietary supplement in various forms, including powders, flakes, capsules, tablets, and liquids. People take brewer’s yeast for many different reasons, although its benefits are not well defined. Common side effects may include an upset stomach, gas, or bloating. Before taking brewer's yeast, make sure to tell your health care provider about any health conditions you have or medicines you are taking.

Uses

What is brewer’s yeast used for?

Brewer’s yeast (Saccharomyces cerevisiae) is a strain of yeast that is commonly used in baking, brewing, and winemaking. It is also used as a dietary supplement for many reasons. However, its benefits are not well defined. Some common reasons people take brewer’s yeast include the following.

• To lower blood sugar levels
• To lower blood pressure
• To lower cholesterol levels
• To increase milk production

Note: The FDA has not reviewed brewer’s yeast for safety and effectiveness. Learn more about dietary supplements here.

How does brewer’s yeast work (mechanism of action)?

Supplements of brewer’s yeast contain live or nonliving yeast strains.

Brewer’s yeast seems to help lower blood sugar levels in certain people with diabetes; it does so by helping insulin work better. Small studies show some benefits. However, there are no large studies to clarify who may benefit the most and what dose of the yeast should be used. Some of the glucose-lowering effect may partly be due to the chromium content in brewer’s yeast. But these benefits are not well defined.

Limited data suggest brewer’s yeast may help lower blood pressure and cholesterol levels in people with diabetes, but these benefits are also not well defined. It is unclear exactly how brewer’s yeast may lower blood pressure. When brewer’s yeast is broken down by the body (metabolized), it is thought to produce a peptide that reduces the activity of angiotensin-converting enzyme, which may then lower blood pressure. The cholesterol-lowering effects may be related to the vitamin B content of brewer’s yeast or to decreased absorption of cholesterol from your gut.

Animal studies show that brewer’s yeast might increase milk supply. The thought is it improves overall nutrition because of the B vitamin and chromium content. However, these benefits are not well defined because there are no human studies to confirm that brewer’s yeast increases milk supply.

Some brewer’s yeast dietary supplements contain many different chemicals. The amounts of each chemical in a specific brewer’s yeast product may vary. Some, none, or all of these chemicals may have effects on the body. These effects may change depending on how much of each chemical is found in the product you are using.

How should I store brewer’s yeast?

You should store brewer's yeast according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.

Side Effects

What are the most common side effects of brewer’s yeast?

The most common side effects of brewer’s yeast are listed below. Side effects may vary depending on the dose you are taking or the specific product you are using. Brewer’s yeast generally seems to be well tolerated. Tell your health care provider if you have any side effects that bother you.

• Upset stomach
• Gas
• Bloating
• Diarrhea

There may be other side effects of brewer’s yeast that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of brewer’s yeast?

While less common, the most serious side effects of brewer’s yeast are described below, along with what to do if they happen.

Severe Allergic Reactions. Brewer’s yeast may cause allergic reactions, which can be serious. Stop using brewer’s yeast and get help right away if you have any of the following symptoms of a serious allergic reaction.

• Breathing problems or wheezing
• Racing heart
• Fever or general ill feeling
• Swollen lymph nodes
• Swelling of the face, lips, mouth, tongue, or throat
• Trouble swallowing or throat tightness
• Itching or skin rash
• Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
• Nausea or vomiting
• Dizziness, feeling lightheaded, or fainting
• Stomach cramps
• Joint pain

Infections. Brewer’s yeast may increase your risk of infections, including serious blood infections, especially if you have immune system problems. Call your health care provider right away if you have an infection or any of the following symptoms.

• Burning or stinging when you pee
• Coughing, or coughing up blood
• Fever, sweats, chills, or muscle aches
• Shortness of breath
• Diarrhea or stomach pain
• Weight loss

Precautions

Who should not use brewer’s yeast?

Allergies to Ingredients. People who are allergic to any of the following should not use brewer’s yeast.

• Yeast
• Any of the ingredients in the specific product

Your pharmacist can tell you all of the ingredients in the specific brewer’s yeast products they stock.

What should I know about brewer’s yeast before using it?

Brewer’s yeast is a dietary supplement that contains Saccharomyces cerevisiae. It cannot be marketed to treat or cure a disease. A specific variant of S. cerevisiae,called S. boulardii, is available as a prescription probiotic.

Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.

Keep brewer’s yeast out of the reach of children.

Some brewer’s yeast products may contain other ingredients, such as trace elements, vitamins, or minerals, including chromium, lithium, B vitamins, or selenium. It is important to read the label carefully to understand which ingredients are in the product you are taking. These other ingredients can have their own side effects and possible interactions.

The FDA has not tested brewer’s yeast products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.

What should I tell my health care provider before using brewer’s yeast?

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if brewer’s yeast is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your health care provider if you have any of the following.

• Weakened immune system
• Diabetes
• High blood pressure
• High cholesterol levels
• Crohn’s disease

Other Medicines and Supplements. Brewer’s yeast may interact with other medicines and supplements. Before taking brewer’s yeast, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Pregnancy. It is not known if or how brewer’s yeast could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.

Breastfeeding. It is not known if brewer’s yeast passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.

Interactions

Does brewer’s yeast interact with foods or drinks?

There are no known interactions between brewer’s yeast and foods or drinks.

It is unknown if drinking alcohol will affect brewer’s yeast.

Does brewer’s yeast interact with medicines (drug interactions)?

Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following.

• A medicine that suppresses your immune system, such as cyclosporine (Gengraf, Neoral, Sandimmune, and others) or mycophenolate (Cellcept and others)
• A medicine for diabetes
• A monoamine oxidase inhibitor (MAOI), which is a medicine usually used for depression or Parkinson’s disease
• Fluconazole (Diflucan), itraconazole (Sporanox, Tolsura), ketoconazole, posaconazole (Noxafil), or voriconazole (Vfend), which is a medicine used for fungal infections
• Griseofulvin (Fulvicin P/G, Gris-PEG, and others), which is a medicine used for certain fungal infections
• Amphotericin B (Abelcet, AmBisome), which is a medicine used to treat fungal infections

The interactions between brewer’s yeast and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with brewer’s yeast is incomplete. Always check with your health care provider before taking brewer’s yeast with any medicines.

Dosing

What should I do if I accidentally use too much brewer’s yeast?

If you or someone else has used too much brewer’s yeast, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

Brewer’s yeast supplements are available in a variety of forms, including flakes, powders, tablets, capsules, and liquids. Read the product label closely and speak to a health care provider about how to use brewer’s yeast safely. Do not take double or extra doses, even if you miss a dose.