The Science Behind Breast Milk Supply: What Every Mom Needs to Know

Breast milk is considered the best food for newborns and infants, providing all the necessary nutrients for growth and development. However, many new mothers worry about their ability to produce enough milk to meet their baby’s needs. Understanding the science behind breast milk production can help new mothers feel confident in nourishing their babies.

How The Body Produces Breast Milk

Breast milk production is controlled by hormones, specifically prolactin, and oxytocin. Prolactin stimulates milk production, while oxytocin helps the milk flow from the mammary glands to the nipple. This process is called lactation, and it begins after childbirth when the baby’s suckling triggers the release of these hormones. The more the baby nurses, the more milk the body produces.

Factors That Affect Breast Milk Supply

Several factors can impact a mother’s milk supply, including:

  • Stress: High-stress levels can interfere with releasing hormones that control lactation.
  • Dehydration: Staying hydrated is important for maintaining a good milk supply.
  • Medications: Certain medications can affect lactation, so it’s important to discuss the use of any medications with a doctor.
  • Insufficient nursing: The demand and supply principle applies to breast milk production. The more the baby nurses, the more milk the body produces.
  • Returning to work or school: For some mothers, the transition back to work or school can reduce the amount of time available for nursing and pumping, leading to a decrease in milk supply.
  • Hormonal imbalances: Certain medical conditions, such as polycystic ovary syndrome (PCOS) and thyroid disorders, can affect hormone levels and lactation.

Increasing Breast Milk Supply

If a mother is concerned about her milk supply, there are several strategies she can try to increase it, including:

  1. Nurse frequently: The more the baby nurses, the more milk the body will produce.
  2. Pump regularly: If a mother cannot nurse as often as she’d like, she can try pumping to stimulate milk production. The best way to increase milk supply when pumping is to ensure that your baby is nursing frequently and effectively. Additionally, you can pump after nursing sessions to increase your milk supply. 
  3. Stay hydrated: Drinking plenty of fluids can help maintain a good milk supply.
  4. Get enough rest: Sleep is important for overall health and can help reduce stress levels.
  5. Eat a balanced diet: A well-balanced diet can help support lactation and overall health.
  6. Seek support: Joining a breastfeeding support group or talking to a lactation consultant can provide encouragement and helpful tips for increasing milk supply.

Understanding Milk Supply and Baby’s Weight Gain

It’s important to remember that weight gain is just one indicator of how well a baby is growing and thriving. A baby’s weight can fluctuate for many reasons, such as increased physical activity or feeding patterns. As long as a baby has enough wet and dirty diapers, is alert and active, and is generally healthy, there’s no need to worry about a temporary decrease in weight gain.

Supplementing with Formula

If a mother feels she is not producing enough milk, she may consider supplementing with formula. However, it’s important to remember that even a small amount of breast milk provides numerous health benefits for the baby. Therefore, before starting to supplement with formula, a mother should talk to her healthcare provider to ensure that it is the right decision for her and her baby.


Breast milk is a vital source of nutrition for newborns and infants. Understanding the science behind breast milk production and the factors that affect it can help new mothers feel confident in their ability to nourish their baby. While some mothers may experience challenges with milk supply, some strategies can help increase it, and supplementing with formula can also be an option. The most important thing is to have open communication with a healthcare provider and to trust in the body’s ability to provide for the baby. Then, with support, education, and a positive attitude, every mother can feel confident in her ability to nourish her baby with breast milk.