Should I Add Brewer’s Yeast To My Postpartum Smoothies?

By Rachelle Mallik, MA, RDN

Reproductive dietitian and founder of The Food Therapist


Breastfeeding postpartum mom

A common question among breastfeeding parents is “What can I eat to boost my milk supply?” Various foods, herbs and supplements are touted as galactogogues, which are substances that increase breast milk production/supply, but the studies on their effectiveness are limited. Brewer’s yeast is often added to lactation bites and cookies, so let’s dig into the research to see why you may (or may not) want to include this ingredient in your postpartum smoothies and diet while breastfeeding. 

What is brewer's yeast?

 brewer's yeast postpartum smoothies

Brewer’s yeast, also known as saccharomyces cerevisiae, is a type of yeast used to produce beer, hence the name. It’s also sold as a dietary supplement, often in a large tub like protein powder. Brewer’s yeast is rich in protein and several B vitamins, including thiamine, riboflavin and B6 (1). The quantity of these B vitamins in breast milk is affected by maternal diet (2), so it’s important for lactating folks to consume enough of them through food and/or supplements. Protein needs also increase during lactation by about 25 additional grams of protein per day. But you don’t need brewer’s yeast to get enough protein or B vitamins in your diet. Many other foods are rich in these nutrients, including but not limited to meat, eggs, legumes, whole grains, milk and yogurt.
Note: brewer’s yeast is not the same thing as nutritional yeast and would not be a good substitute for brewer’s yeast in a smoothie or lactation cookie recipe. Nutritional yeast also provides B vitamins and protein, but is better suited to savory foods and is delicious sprinkled on stove-top popcorn.

What the research says about brewer's yeast to support lactation


While brewer’s yeast is often used as a galactagogue, there is little evidence to support this. No human studies have shown that taking brewer’s yeast increases milk supply. Studies in cows have shown a connection, but this is attributed to improved nutrition from consuming brewer’s yeast rather than a specific effect on lactation (3).

Safety concerns

Speak to your healthcare provider before supplementing with brewer’s yeast as it can interact with some medications. Additionally, some people may experience gastrointestinal side effects when taking brewer’s yeast (4). Brewer’s yeast should not be consumed by folks with celiac disease unless the product is labeled gluten-free (5).



lactation cookie postpartum smoothie energy balls

Anecdotally, some people say that brewer’s yeast helps boost their milk supply. As a dietitian who works with lactating clients, I generally recommend addressing any root issues that may be contributing to low milk supply (e.g. the frequency of feeding/pumping sessions, baby’s latch), and working with a lactation consultant if needed. It’s also important to eat a varied diet that provides enough energy and fluid to meet your estimated needs before adding in supplements in an effort to boost milk supply. Eating less than 1800 calories a day may cause a decrease in milk supply (6), so make sure you’re eating regular meals and snacks throughout the day.


If you choose to add brewer’s yeast to your breastfeeding diet and have discussed it with your healthcare provider, look for a reputable brand that carries powdered brewer’s yeast with no added ingredients. Brewer’s yeast can be very bitter so you can buy one labeled “reduced bitterness” or “debittered”. Unfortunately there are no clear guidelines on how much to consume nor how often for lactation. Typical dosing as indicated on nutrition labels for brewer’s yeast is two tablespoons. It can be mixed into recipes for lactation cookies, energy balls, and postpartum smoothies. The team at Leto Foods likes adding two teaspoons to our Decaf for a satisfying postpartum smoothie.


Disclaimer: The information provided on this site is for educational purposes only, and does not substitute for medical advice. Always consult a medical professional or healthcare provider related to medical advice, diagnoses, or treatment.


About the Author:


Rachelle Mallik MA, RDN is a registered dietitian nutritionist and the founder of The Food Therapist, a telehealth practice specializing in fertility, pregnancy, postpartum and breastfeeding. Rachelle supports her clients with an evidence-based, weight-inclusive approach that focuses on health-promoting behaviors and nourishment over restriction. She has presented at various events in the Chicago area and nationally to educate the community and fellow healthcare providers on nutrition for reproductive health. Rachelle is an active member of the American Society for Reproductive Medicine and their Nutrition Special Interest Group. She earned a Bachelor's degree in Human Nutrition from the Barrett Honors College at Arizona State University and a Master's degree in Food Studies from New York University. Follow her at @RachelleMallik on Instagram and visit her website for information on her services.



(1) Mount Sinai Health Library: Brewer’s Yeast. Accessed 10 Feb 2022 ​​


(2) Allen, L. B Vitamins in Breast Milk: Relative Importance of Maternal Status and Intake, and Effects on Infant Status and Function. Adv Nutr. 2012 May; 3(3): 362–369.

(3) Brewer’s Yeast. Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2021 Dec 20.


(4) Natural Medicines Database: Brewer’s Yeast. Accessed 10 Feb 2022,-herbs-supplements.aspx


(5) “Is Yeast Gluten-Free?” Beyond Celiac Accessed 10 Feb 2022


(6) Losing Weight While Breastfeeding. Eileen Behan, RDN, LD. Published August 19, 2019. Reviewed June 2019