Background

Brewer's yeast (Saccharomyces cerevisiae) is used in beer brewing. It is sometimes used as a food additive and is also available as a dietary supplement.

Some brewer's yeast products contain live yeast, while others contain non-living yeast. Brewer's yeast is a source of B vitamins and protein. It also contains chromium, which might help the body use insulin better and lower blood sugar levels. Brewer's yeast also seems to increase enzymes in the stomach that could relieve diarrhea and improve the body's defense against viral infections like the flu.

People use brewer's yeast for diabetes, flu, diarrhea, high cholesterol, and other conditions, but there is no good scientific evidence to support these uses.

Safety Safety definitions

When taken by mouth: Brewer's yeast is possibly safe for most people when taken short-term. A specific brewer's yeast product (EpiCor by Embria Health Sciences) that contains dried, non-living yeast has been safely used in doses of 500 mg daily for 12 weeks. Other brewer's yeast products that contain living yeast have been safely used in doses of 4-8 billion colony-forming units daily for up to 12 weeks. In some people, brewer's yeast can cause headache, stomach discomfort, and gas (flatulence).

There isn't enough reliable information to know if brewer's yeast is safe to use long-term or what the side effects might be. Stick with short-term use.

When applied to the skin: There isn't enough reliable information to know if brewer's yeast is safe or what the side effects might be.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if brewer's yeast is safe to use when pregnant or breast-feeding. Stay on the safe side and avoid use.

Crohn disease: Brewer's yeast can make Crohn disease worse. Don't use brewer's yeast if you have Crohn disease.

Weakened immune system: There is some concern that brewer's yeast might increase the risk of blood infections in people with weakened immune systems. This includes people with HIV/AIDS or cancer, or people who have taken medicines to prevent rejection of a transplanted organ. If you have a weakened immune system, talk with your healthcare provider before taking a brewer's yeast supplement.

Effectiveness

Dosing & administration

There isn't enough reliable information to know what an appropriate dose of Brewer's yeast might be. 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 a healthcare professional before using.

Interactions with pharmaceuticals

Lithium

Interaction Rating=Moderate Be cautious with this combination.

Some brewer's yeast contains lithium. Taking brewer's yeast along with lithium might increase how much lithium is in the body and result in serious side effects. Talk with your healthcare provider before using this product if you are taking lithium.

Medications for depression (MAOIs)

Interaction Rating=Major Do not take this combination.

Brewer's yeast contains a chemical called tyramine. Large amounts of tyramine can cause high blood pressure. Some medications used for depression stop the body from breaking down tyramine. This can cause too much tyramine in the body and dangerously high blood pressure.

Medications for diabetes (Antidiabetes drugs)

Interaction Rating=Moderate Be cautious with this combination.

Brewer's yeast might lower blood sugar levels. Taking brewer's yeast along with diabetes medications might cause blood sugar to drop too low. Monitor your blood sugar closely.

Medications for fungal infections (Antifungals)

Interaction Rating=Minor Be watchful with this combination.

Brewer's yeast is a yeast (a fungus). Medications for fungal infections help reduce fungus in and on the body. Taking brewer's yeast with medications for fungal infections can reduce the effects of brewer's yeast.

Interactions with herbs & supplements

Chromium-containing herbs and supplements: Brewer's yeast contains chromium. Taking it with other supplements that contain chromium can increase the risk of chromium poisoning. Examples of supplements that contain chromium include bilberry, cascara sagrada, and horsetail.
Herbs and supplements that might lower blood sugar: Brewer's yeast might lower blood sugar. Taking it with other supplements with similar effects might lower blood sugar too much. Examples of supplements with this effect include aloe, bitter melon, cassia cinnamon, chromium, and prickly pear cactus.

Interactions with foods

There are no known interactions with foods.