Brewer’s Yeast & Beer as a Galactagogue: Myth vs. Science

For centuries, beer has been rumored to help boost milk supply, making its way into folklore, cultural traditions, and even modern-day conversations about lactation. From dark stouts to homemade barley brews, the idea that beer can support breastfeeding has stood the test of time—but is it fact or fiction?

Let’s look at the historical origins of beer as a galactagogue, bust some common myths, and explore a safer, alcohol-free alternative: Brewer’s Yeast.

The belief that beer could help lactating parents produce more milk has its roots in ancient and medieval traditions:

• In medieval Europe, midwives often advised new mothers to drink a small glass of beer to encourage lactation (1).

• Many indigenous cultures also had variations of fermented barley drinks, thought to aid in postpartum healing and breastfeeding (2).

• Barley, one of beer’s primary ingredients, contains phytoestrogens—plant compounds that mimic estrogen, a hormone involved in milk production (3).

This connection likely helped cement the idea that beer could “open the floodgates” for breastfeeding parents. Even into the 20th century, hospitals and midwives encouraged new mothers to drink a small amount of dark beer, like Guinness, to support lactation (4).

In the Middle Ages, beer was often safer to drink than water because of its fermentation process, which killed off bacteria (1).

💡 The Myth: Since nursing mothers drank beer regularly, people assumed it must be helping with milk production.
💡 The Reality: The benefits were likely from barley and brewer’s yeast, as well as basic levels of hydration, not alcohol.

In parts of Germany and Belgium, dark beer (like stouts and porters) was recommended to new mothers (4).

💡 The Myth: Darker beers = richer milk.
💡 The Reality: Milk composition is driven by maternal nutrition, not beer color.

Guinness famously ran an ad campaign in the early 20th century with the tagline "Guinness is good for you" (5).

💡 The Myth: Guinness boosts milk supply because of its iron content.
💡 The Reality: While iron is beneficial postpartum, beer isn't the best way to get it.

Some traditions suggest a cold beer helps relax nursing mothers, making letdown easier (6).

💡 The Myth: A beer before breastfeeding = better milk flow.
💡 The Reality: Alcohol actually suppresses oxytocin, reducing milk ejection (7).

While barley contains compounds that may support lactation, the alcohol in beer can actually work against milk production. There is no evidence that beer boosts milk production.

🍺 Alcohol suppresses oxytocin , the hormone responsible for letdowns (7).
🍼 Studies show regular alcohol can decrease overall milk production and impact baby’s feeding behaviors (8).
🚫 Alcohol impacts breast milk , as it takes 2 hours for a drink to clear the system (7).

Brewer’s yeast ( Saccharomyces cerevisiae ) has been used for centuries in fermentation, primarily for brewing beer and baking bread. Historically, its nutritional properties were recognized long before modern science could explain them.

This yeast is rich in B-complex vitamins (including B1, B2, B3, B6, and B12), protein, selenium, iron, chromium, and essential amino acids—all of which are crucial for postpartum recovery and energy production (9). The high B-vitamin content plays a role in maternal metabolism, combating postpartum fatigue and supporting overall well-being (10).

Brewer’s yeast is also a natural source of beta-glucans, which may contribute to immune system support and gut health—both essential for a recovering postpartum body (11). Brewer’s yeast has been widely used in lactation support due to its nutrient profile and possible role in prolactin regulation, a key hormone in milk production (12).

Many lactating parents incorporate brewer’s yeast into their diets through lactation cookies, smoothies, and supplements as a safe, alcohol-free way to support breastfeeding. Unlike beer, which contains alcohol that can inhibit oxytocin and reduce milk supply, brewer’s yeast provides the nutritional benefits historically associated with beer without the risks (7).

Adding brewer’s yeast to your diet is simple and delicious. It has a slightly nutty, savory flavor that pairs well with sweet or hearty foods.

One of the most popular ways to enjoy brewer’s yeast is in lactation cookies ! Here’s a simple go-to recipe:

Ingredients:

• 2 cups rolled oats

• 1 cup flour (or almond flour)

• 1/2 cup coconut oil or butter

• 1/2 cup coconut sugar or maple syrup

• 2 tbsp brewer’s yeast

• 1 tbsp flaxseed meal

• 1 egg

• 1 tsp vanilla extract

• 1/2 tsp cinnamon

• 1/2 tsp baking soda

• 1/2 cup chocolate chips (optional)

Instructions:

1️⃣ Preheat oven to 350°F.

2️⃣ Mix wet ingredients in one bowl, dry in another.

3️⃣ Combine, scoop onto a baking sheet, and bake for 10-12 min.

4️⃣ Enjoy & feel good knowing your cookies are packed with postpartum-friendly nutrients!

For a quick nutrient boost, blend up a brewer’s yeast lactation smoothie:

🥛 1 cup almond milk or oat milk
🍌 1 frozen banana
🥄 1 tbsp brewer’s yeast
🌰 1 tbsp peanut or almond butter
🍯 1 tsp honey or maple syrup
🧊 A handful of ice

Blend and enjoy a creamy, nourishing treat!

If you prefer a non-sweet way to enjoy brewer’s yeast, sprinkle it over:

✔️ Avocado toast 🥑
✔️ Roasted veggies 🥕
✔️ Scrambled eggs 🍳

It adds a mild umami flavor , almost like nutritional yeast!

❌ Beer isn’t a reliable galactagogue —its alcohol content can actually hinder milk production.
✅ Brewer’s yeast is a safe, nutrient-rich option that supports postpartum health.
🍀 This St. Patrick’s Day, consider celebrating with a lactation-friendly smoothie instead of a pint! 

1. Brüssow, H. (2020). The History of Fermentation. Microorganisms, 8(8), 1141. https://doi.org/10.3390/microorganisms8081141

2. Mead, M. (1965). Fermented Beverages in Traditional Societies. American Anthropologist, 67(5), 174-187. https://doi.org/10.1525/aa.1965.67.5.02a00030

3. Setchell, K. D. R. (1998). Phytoestrogens and Estrogenic Effects. The Journal of Nutrition, 128(3), 612-617. https://doi.org/10.1093/jn/128.3.612

4. Schivelbusch, W. (1992). Tastes of Paradise: A Social History of Spices, Stimulants, and Intoxicants. Vintage Books.

5. Guinness Archive. "Guinness is Good for You," (1920s). Retrieved from  https://www.guinness.com

6. Fink, J., Wagner, C., & Mitchell, B. (2018). Galactagogues and Lactation. Current Nutrition Reports, 7(3), 144-156. https://doi.org/10.1007/s13668-018-0238-8

7. Haastrup, M. B., et al. (2014). Alcohol and Breastfeeding. Basic & Clinical Pharmacology & Toxicology, 114(2), 168-173. https://doi.org/10.1111/bcpt.12149