All Blogs | When Does Breast Milk Start and How Is It Made?

All Blogs | When Does Breast Milk Start and How Is It Made?

When Does Breast Milk Start and How Is It Made?

Welcoming a new baby into the world is a miraculous journey, and for many mothers, this includes the unique experience of breastfeeding. Understanding how and when breast milk starts, and the nuances of milk production, can empower and reassure expecting and breastfeeding mamas. In this blog, we'll explore the intricate process of how breast milk is made, the signs of lactation, and factors that may influence milk supply.

How is Breast Milk Made Within the Body?

The creation of breast milk is a fascinating and complex biological process. It's a perfect blend of nature's ingenuity and a mother's physiological adaptability. Here's a deeper look into how breast milk is produced within a mother's body.

Hormonal Orchestra

The journey of milk production, scientifically known as lactogenesis, is orchestrated by a symphony of hormones. During pregnancy, the body's increased levels of estrogen and progesterone stimulate the growth of milk-producing glands in the breasts. These hormonal changes prepare the breast tissue for the vital role of feeding the newborn.

The Prolactin Factor

Prolactin, nicknamed the 'milk-producing hormone,' plays a pivotal role. It's released by the pituitary gland, especially in response to the baby's suckling. Prolactin signals the alveoli — tiny milk-producing cells in the breast — to start producing milk.

Colostrum – The First Milk

In the later stages of pregnancy, the breasts may start to produce colostrum. This thick, yellowish milk is packed with nutrients and antibodies. It's designed to provide the newborn with a powerful nutritional start, even in small quantities.

Milk Ejection Reflex (Let-Down)

When the baby latches onto the breast and begins to nurse, a signal is sent to the brain, releasing oxytocin. This hormone causes the tiny muscles around the areola to contract, pushing the milk through the ducts toward the nipple, a process often referred to as the 'let-down reflex.'

Transitional to Mature Milk

After the initial production of colostrum, the breasts begin to produce transitional milk, a combination of colostrum and mature milk. Over the next two weeks, this transitional milk gradually becomes mature milk, which has a thinner consistency and higher volume to meet the growing demands of the baby.

Feedback Inhibitor of Lactation (FIL)

The breasts use a feedback mechanism to regulate milk production. A substance called FIL in the milk signals the breast to slow down production when the breast is full and to increase production when the breast is emptied regularly. This ensures a balance between milk supply and the baby’s demand.

Nutritional Balance 

Breast milk composition can change from one feeding to the next. It adapts to the nutritional needs of the baby, with variations in fat, sugar, water, and protein content. This dynamic nature of breast milk ensures that breastfed babies receive what they need for their development.

This miraculous process showcases the body's innate wisdom in nurturing life. For many breastfeeding moms, understanding these biological mechanisms can be both empowering and reassuring, as they navigate the beautiful yet sometimes challenging journey of breastfeeding.

lactation nurse helping new mother breastfeed

When Does Breast Milk Start?

The initiation of breast milk production is intricately timed with the journey of childbirth and early motherhood. Understanding when breast milk begins to form helps in preparing expecting and new mothers for the breastfeeding journey ahead. 

Early Stages - Colostrum Formation

The body starts preparing for breastfeeding long before the baby arrives. As early as the second trimester of pregnancy, the breasts begin to produce colostrum, the first form of breast milk. As mentioned earlier, this early milk, often referred to as ‘liquid gold’ due to its rich yellow color and invaluable nutrients, is thick and concentrated. It’s packed with antibodies and immunoglobulins crucial for bolstering the baby’s immune system.

Birth Triggers a Shift

The actual commencement of milk production is closely linked to the delivery of the baby. The dramatic drop in hormones like progesterone following childbirth acts as a trigger for the body to ramp up milk production. This hormonal shift signals the breasts to transition from producing colostrum to producing more substantial quantities of milk.

First Few Days - Transitional Milk

In the first few days after birth, as the colostrum gradually decreases, transitional milk begins to appear. This milk is a mix of colostrum and the coming mature milk. It contains higher levels of fat and lactose, providing more energy to the rapidly growing newborn.

The Arrival of Mature Milk

By approximately 10 to 15 days postpartum, the breast milk transitions to what is known as mature milk. This final stage of milk production consists of foremilk, the thinner milk that comes at the start of a feeding, and hindmilk, the richer, fattier milk that comes after the initial flow. This mature milk is designed to meet the full nutritional needs of the baby, evolving in composition as the baby grows and its nutritional requirements change.

Individual Variations

It’s important to note that the timeline for when breast milk starts can vary from mother to mother. Factors such as the mother's health, the birthing process, and how frequently the baby feeds can influence when milk production increases. Some mothers may experience a faster transition to mature milk, while others may take a bit longer.

Role of Frequent Feeding

Early and frequent breastfeeding is crucial in establishing and maintaining a healthy milk supply. Breastfeeding or expressing milk soon after birth and then frequently thereafter encourages more rapid milk production and helps ensure a steady milk supply as the baby grows.

Understanding the timeline and changes in breast milk production can provide reassurance and guidance to expecting and new mothers. It emphasizes the natural, tailored process through which their bodies nourish and support their newborns.

Lactation Signs and Symptoms

Recognizing the signs and symptoms of lactation is essential for new and expecting mothers. These indicators not only signal that the body is preparing to feed the baby but also help mothers understand and connect with their breastfeeding journey. 

lactation signs & symptoms

Breast Changes

One of the earliest signs of lactation is the change in the breasts themselves. As pregnancy progresses and after childbirth, many women notice their breasts becoming fuller, larger, and more sensitive or tender. This is due to the increased blood flow and the expansion of the mammary glands in preparation for milk production.

Colostrum Leakage

Even before the baby is born, some mothers may notice small amounts of colostrum leaking from their nipples. Colostrum leakage is a clear sign that the body is gearing up for breastfeeding.

Tingling Sensation

Many breastfeeding moms experience a tingling or prickling sensation in their breasts, often during nursing or when it’s time to feed the baby. This sensation is associated with the milk 'let-down' reflex, a natural response where the milk is pushed down the ducts towards the nipple.


A few days postpartum, as the breasts transition from producing colostrum to more mature milk, mothers may experience engorgement. This is when the breasts feel extremely full, firm, and sometimes painful. Engorgement is due to the increased milk production and blood flow to the breasts and is a common sign that the milk supply is establishing.

Milk Ejection

With the onset of regular nursing or pumping, some mothers can visibly see the milk ejection or let-down. This may happen on one or both sides and can sometimes occur spontaneously, even when not feeding or pumping.

Changes in Breast Appearance Post-Feeding

After feeding or pumping, many mothers notice their breasts appear less full and feel softer. This change indicates that the baby is effectively extracting milk, and the breasts are responding by producing and releasing milk.

Increased Thirst and Hunger

Breastfeeding can increase a mother's need for hydration and nutrition. Many mothers report feeling more thirsty and hungry, which is the body’s way of ensuring it has enough resources to produce milk.

Emotional Responses

Some women experience emotional signs linked with lactation, such as a feeling of calmness or a strong sense of bonding during nursing. These emotional responses are partly due to the release of hormones like oxytocin, which is known for enhancing maternal behaviors and emotions.

Recognizing these signs and symptoms can help mothers better understand and manage their lactation process. It's a unique and individual experience; some may experience all these symptoms, while others may notice only a few. Understanding these signs helps mothers to tune in to their bodies' cues and respond to their baby's needs effectively.

Why Might Breast Milk Production Not Increase Right Away?

For some new mothers, there might be a delay in the increase of milk volume. Several factors can contribute to delayed milk production. This delay can be due to various reasons, such as the stress of childbirth, inadequate breastfeeding techniques, or infrequent nursing. Medical conditions can also impact milk supply. Additionally, certain medications, previous breast surgeries, may also play a role. Emotional factors, like stress or anxiety, can also affect the milk production process. It's important for breastfeeding moms to seek support, from a lactation consultant, and your healthcare provider to address these challenges. Consulting with a lactation consultant can provide personalized guidance and support to enhance breast milk production.

If you’re looking for a simple way to support your milk production after giving birth, try adding a Milkflow drink mix or capsule to your daily routine. They’re made with lactation consultant-recommended ingredients like fenugreek and moringa.

green heart and green light bulb

Breastfeeding is a journey unique to each mother and baby duo. Understanding the process of breast milk production, being aware of the signs of lactation, and knowing what factors might influence your milk supply are key to a successful breastfeeding experience. Remember, every mother's journey is different, and it's okay to seek help from a lactation consultant. Embrace your journey with confidence and kindness, knowing you are doing an incredible job nourishing your little one.