Lactation cookies are built around a handful of ingredients thought to boost milk supply: oats, brewer’s yeast, flaxseed, and sometimes fenugreek. These ingredients are classified as galactagogues, substances believed to promote lactation. The theory behind them is reasonable, but the clinical evidence tells a more complicated story. A 2023 randomized controlled trial found no measurable difference in milk production between mothers eating lactation cookies and mothers eating regular cookies of the same size and calorie count.
The Key Ingredients and What They’re Supposed to Do
Most lactation cookie recipes, whether homemade or commercial, rely on some combination of oats, brewer’s yeast, flaxseed, and fenugreek. Each brings a different proposed mechanism to the table, though none has been definitively proven to increase human milk supply on its own.
Oats contain beta-glucan, a type of fiber found in the cell walls of cereal grains. Beta-glucan has known effects on the immune system, and some researchers have hypothesized that because immune disruption can impair lactation, supporting immune function could indirectly support milk production. That’s a plausible chain of reasoning, but it hasn’t been confirmed in human breastfeeding studies. Oats also provide iron, B vitamins, and complex carbohydrates, all of which support the extra energy demands of nursing.
Brewer’s yeast is the second most commonly used galactagogue after lactation cookies themselves, used by about 32% of Australian women surveyed in a large study. Like oats, brewer’s yeast contains beta-glucan. It’s also rich in B vitamins and chromium. Animal studies suggest it may increase milk supply, but researchers attribute this to improved overall nutrition rather than any direct effect on lactation hormones.
Flaxseed is a source of alpha-linolenic acid (an omega-3 fat) and phytoestrogens, plant compounds that are structurally similar to estrogen. In animal studies, flaxseed consumption during lactation raised levels of estradiol and leptin in mothers and altered milk composition. The theory is that phytoestrogens could interact with estrogen receptors in breast tissue, potentially influencing milk-producing cells. However, the same animal research also found that flaxseed during lactation affected offspring body composition and hormonal development, so the picture is not straightforward.
Fenugreek appears in some cookie recipes and is one of the most widely studied herbal galactagogues. It contains phytoestrogens and a compound called diosgenin. The proposed mechanism works two ways: phytoestrogens may bind to receptors on mammary gland cells and stimulate the growth of milk-producing tissue, and they may also act as dopamine blockers. Since dopamine suppresses prolactin (the hormone that drives milk production), blocking dopamine could raise prolactin levels. One study of postpartum fenugreek supplementation found increases in prolactin, though researchers note the exact mechanism remains undefined.
What the Clinical Trial Actually Found
In 2023, researchers published the first randomized controlled trial specifically testing lactation cookies. They assigned 176 mothers to eat either cookies containing the classic galactagogue ingredients (oatmeal, brewer’s yeast, flaxseed, and fenugreek) or conventional cookies matched for weight, calories, and appearance but without those ingredients. After one month of daily consumption, both groups saw nearly identical increases in milk production: 5.5 mL per hour in the lactation cookie group and 5.8 mL per hour in the control group. The difference was statistically meaningless, with a p-value of 0.948.
Both groups produced more milk than at the start of the study. That detail matters, because it suggests something else was going on. The simple act of eating a calorie-dense snack every day, or the psychological reassurance of doing something proactive about milk supply, may have contributed to the improvement in both groups.
Why So Many People Say They Work
Despite the trial results, plenty of mothers report noticeable increases in supply after eating lactation cookies. Several factors could explain this without the galactagogue ingredients being responsible.
Breastfeeding burns roughly 340 to 400 extra calories per day. Many new mothers are sleep-deprived, stressed, and eating irregularly. A calorie-dense cookie provides quick energy, and simply meeting your body’s caloric needs can support milk production that was being held back by an energy deficit. The cookies also tend to be high in whole grains, healthy fats, and iron, all nutrients that matter during lactation.
There’s also a strong psychological component. Stress and anxiety are known to interfere with the letdown reflex. If eating a lactation cookie makes you feel like you’re actively supporting your supply, that reduced anxiety could have a real physiological effect. Placebo responses in breastfeeding are well-documented, and there’s nothing wrong with benefiting from one.
Timing plays a role too. Milk supply naturally fluctuates and tends to regulate over the first several weeks postpartum. Many mothers start lactation cookies during a perceived dip, and supply would likely have recovered on its own. Without a control group (which most mothers obviously don’t have), it’s easy to credit the cookies.
The Ingredients Still Have Nutritional Value
Even without proven galactagogue effects, the core ingredients in lactation cookies are genuinely nutritious for breastfeeding mothers. Oats provide sustained energy and soluble fiber. Brewer’s yeast delivers B vitamins, protein, and minerals. Flaxseed adds omega-3 fatty acids and additional fiber. These are all foods that support postpartum recovery and general health, whether or not they directly increase milk volume.
The main thing to watch is sugar content. Many commercial lactation cookies are heavily sweetened, and eating several per day can add a significant amount of added sugar to your diet. If you enjoy them, choosing versions with less sugar or making your own gives you more control. Treating them as an occasional nutrient-dense snack rather than a medical intervention is a reasonable approach.
What Actually Increases Milk Supply
Milk production is primarily driven by demand. The more frequently and effectively milk is removed from the breast, the more the body produces. This feedback loop is the most reliable way to increase supply. Feeding or pumping more often, ensuring a good latch, and avoiding long gaps between sessions all send stronger signals to produce more milk.
Adequate hydration, sufficient calories, and rest also support production, though they work by preventing supply from dropping rather than boosting it above baseline. If you’re eating enough, drinking enough, and removing milk regularly, you’re covering the factors that have the strongest evidence behind them. Lactation cookies can fit into that picture as a convenient, satisfying snack. They just aren’t the active ingredient most people assume they are.