6 Reasons You May Experience a Breast Milk Supply Slump

Feel like you're not producing enough breast milk to keep your little one satisfied? Discover why it happens, so you can stop worrying.

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Somewhere along your journey as a nursing mother, you will question your breast milk supply. It can seem as if you have finally gotten into a groove with nursing, and then suddenly your infant's behavior changes—he's nursing more often, nursing at both breasts when he only used to nurse on one side, or appearing to be on a nursing strike. Often these milk slumps aren't permanent, and if you know they're coming, you can plan for them. Here are the top six reasons why milk slumps happen.

Growth Spurts

An infant's first year of life is a time of rapid growth. One night you put your little one to sleep in a one-piece pajama that fits just perfectly, and the next morning the entire outfit seems to have shrunk.

Full-term infants tend to have growth spurts in predictable patterns. The first growth spurt happens shortly after a mother's milk volume increases—between three to seven days postpartum. After that you'll typically see growth spurts at three weeks, six weeks, three months, and six months.

During a growth spurt, it's normal for an infant to suddenly begin to nurse 14 to 16 times a day with shorter breaks between nursing sessions. Growth spurts typically last anywhere from three to five days, sometimes stretching to a week. I receive countless calls a week from mothers worried that their milk supply has suddenly dropped because their infant is "constantly nursing" and "never seems satisfied."

Many mothers worry that during a growth spurt they simply won't have enough milk to meet their infant's high demands. However, every time your infant nurses and "demands" milk, he is telling your body to make more milk. The best thing you can do to increase your milk supply is nurse, and growth spurts provide more than enough opportunities to do so.

Returning to Work or School

Working outside the home can present a unique set of challenges to the breastfeeding mother. While an electric breast pump is an indispensable tool to the working mother, it isn't perfect. Breast pumps can't draw milk from the breast as effectively as a baby. However, to maintain your milk supply during any separation, expressing milk is a must. They key is making time to pump, even when you have a busy schedule. I recommend pumping with a hands-free bustier to allow you to multitask.

Because breast pumps typically yield a much smaller output of milk than nursing, some mothers might have to pump twice to get one bottle worth of milk for their little ones. While this is totally normal, it still presents a challenge to pumping moms. This is where galactagogues come in. These milk-boosting foods and medications can be an incredibly useful tool in helping to boost your breast milk while separated from your little one.


Another common pitfall is trying to provide more milk than is necessary because an infant is being overfed. Some mothers who have an oversupply might be able to consistently pump enough milk to overfeed a baby, but most will not. Most babies can drain a bottle so fast that their stomach doesn't have time to tell their brain that they are full.

An infant's maximum stomach capacity is only five ounces, and most breastfed babies only need three to four ounces in a bottle to meet their nutritional needs. Unlike formula, breast milk changes with the baby, and your little one's ability to digest and absorb nutrients from your milk also changes. Because of this, your infant does not need to take in a larger quantity of breast milk as he gets older. If your infant is consistently drinking more than four ounces of milk in a bottle, then it's time to begin paced feedings to allow time for your infant's stomach to tell his brain that it's full.

Welcome Back, Aunt Flo!

For some women, their menstrual cycle returns within three months postpartum, and for others, eighteen months postpartum. When a woman's menstrual cycle returns, this typically signals the beginning of hormone-mediated milk supply changes throughout the month. Most mothers report that one to two days before the onset of their period as well as the first two to three days of their period, their milk supply drops. In addition to a drop in supply, the hormones related to menstruation also cause changes in the milk's taste. This drop in milk supply is normal and transient. Typically, a mother will still make enough milk to nourish her child effectively but your babies nursing habits and schedule might change a bit during this time.


Some cultures believe that stress spoils a mother's breast milk. While we know that this isn't true, the origins of this folk belief are based in fact. When a mother is under a great deal of stress, her milk supply typically begins to decline. Stress inhibits the release of oxytocin, which is an essential component in the milk eject reflex referred to as letdowns; because of this, an infant may take longer than usual to get the milk he needs.


Every day I find myself sitting across from mothers who report going long stretches between meals, not snacking enough and depriving themselves of the necessary nutrients every mother needs to be able to make milk effectively while also staying healthy. When it comes to nourishing our bodies, you help your child by helping yourself. Breastfeeding can burn up to 600 additional calories a day which means that you need to consistently eat three meals and two to three snacks a day to ensure that you are meeting your nutrient needs. Drastically losing weight or depriving yourself of the calories and nutrients your body needs will eventually take a toll on your milk supply. This isn't to say that trying to lose weight while breastfeeding is completely off the table. However, any diet that is incredibly restrictive in calories is likely to hurt your milk supply. Consider this license to make sure you eat—and that you eat well—as a new mom.

Alicia C. Simpson, MS, RD, IBCLC, LD, is an International Board Certified Lactation Consultant and registered dietitian specializing in maternal and pediatric nutrition. The executive director and founder of the nonprofit Pea Pod Nutrition and Lactation Support, she provides nutrition and breastfeeding education to mothers. In addition to Boost Your Breast Milk, she has written three cookbooks, including Quick and Easy Vegan Comfort Food, and lives in Atlanta, Georgia.