Is Low Milk Supply Hereditary? Genetics and Your Breastfeeding Journey

Q: What are the main genes that affect milk supply?

Recent research has identified the MFGE8 gene as a significant factor in milk secretion. Other studies have found that genes like PLIN4 and GLP1R may be more active in those with lower supply, while KLF10 is often more active in high producers. These genes influence how mammary tissue develops and how milk is released.

Posted on April 01, 2026

Is Low Milk Supply Hereditary? Understanding Your Genetics and Breastfeeding Success

Introduction
The Science: Can You Inherit a Low Milk Supply?
When Hereditary Conditions Impact Supply
The Generational Gap: Perceived vs. Actual Supply
Signs of True Low Milk Supply
Overcoming Genetic Challenges
The Mental Load of Low Supply
Practical Steps to Take Now
Conclusion
FAQ

Introduction

If you have ever sat in a rocking chair at 2:00 AM wondering if your body is doing what it should, you are not alone. Many new parents worry about their milk production. Often, that worry leads to a specific question: "Is low milk supply hereditary?" You might remember your own mother or grandmother mentioning that they "just didn't have enough milk" or that their "milk dried up" early on. It is natural to wonder if your genetic makeup has already decided your breastfeeding outcome before you even start.

At Milky Mama, we believe that knowledge is one of the most powerful tools in your parenting toolkit. We are here to help you navigate the complex world of lactation with evidence-based information and a heavy dose of encouragement. This article explores recent scientific findings regarding genetics and milk supply, the difference between perceived and actual low supply, and how you can support your body’s unique journey.

While researchers are discovering that genetics can play a role in how much milk a person produces, your DNA is not a fixed blueprint for your success. Understanding the science behind milk production can help you feel more empowered and less anxious about your feeding goals.

The Science: Can You Inherit a Low Milk Supply?

For a long time, the common belief was that low milk supply was almost entirely caused by external factors. These factors usually include how often a baby latches or how effectively a pump removes milk. However, recent scientific studies are beginning to show that genetics may play a bigger role than we once thought. Learning more about the science of milk production and supply and demand can help put these factors into perspective.

The Role of the MFGE8 Gene

A significant study conducted by the Penn State College of Medicine looked at why some women stop breastfeeding earlier than they planned. The researchers focused on a condition called Perceived Inadequate Milk Supply (PIMS). This is when a parent feels their milk supply is not enough to meet their baby's needs, even if they want to continue breastfeeding.

The study analyzed the DNA of 88 women. The researchers looked at 18 specific genes that are active in mammary tissue, which is the specialized tissue in the breast responsible for making milk. They found that a specific variation in a gene called MFGE8 was much more common in women who reported low milk supply.

This gene is involved in how the body secretes milk. When a parent has a specific mutation or change in this gene, their body might naturally produce a lower volume of milk compared to others. This does not mean they cannot produce milk at all. It simply means their "baseline" production might be lower, or their body might be more sensitive to challenges like stress or lack of sleep.

RNA and Gene Expression in Breast Milk

Another study from the University of California, San Francisco (UCSF), looked at the actual cells found in breast milk. Breast milk is not just liquid nutrition. It contains immune cells, stem cells, and RNA. RNA is a molecule that carries genetic instructions from your DNA to tell your cells what to do.

The UCSF researchers found that the expression of certain genes—essentially how "active" those genes are—differed between people with high, normal, and low milk supplies. For example, they found that people with lower milk production often had higher levels of a gene called PLIN4. This gene is related to how fats are stored in the body. On the other hand, high producers had higher levels of a gene called KLF10, which helps with the development and function of the mammary glands.

Key Takeaway: Science shows that genetic markers and gene expression can influence milk production. If you feel like you are struggling more than others, there may be a biological reason behind it.

When Hereditary Conditions Impact Supply

While specific "milk genes" are still being researched, we already know that many medical conditions that run in families can impact lactation. If your mother or sister had these conditions, you might also have them, which could indirectly affect your supply.

Polycystic Ovary Syndrome (PCOS)

PCOS is a common hormonal disorder that often runs in families. It can affect how the breast tissue develops during puberty and pregnancy. For some people with PCOS, the mammary glands do not develop fully, leading to a condition called Insufficient Glandular Tissue (IGT).

PCOS also involves insulin resistance, which is when the body’s cells don’t respond well to insulin. Insulin is a hormone that helps your body use sugar for energy. Research suggests that insulin plays a vital role in the "let-down reflex," which is the process where milk is released from the small sacs in your breast into the milk ducts. If insulin levels are imbalanced, it can make it harder for the body to produce and release milk.

Thyroid Dysfunction

Thyroid issues, such as hypothyroidism (an underactive thyroid), are frequently hereditary. The thyroid gland regulates your metabolism and influences almost every hormone in your body, including prolactin and oxytocin.

Prolactin is the hormone responsible for making milk, while oxytocin is the hormone that triggers the release of that milk. If your thyroid is not functioning correctly, your body may struggle to produce enough prolactin to maintain a robust milk supply.

Diabetes and Insulin Resistance

Like PCOS, both Type 1 and Type 2 diabetes can run in families. Because insulin is a key player in the lactation process, any condition that affects insulin production or sensitivity can lead to a delay in "milk coming in" after birth. This is known as delayed lactogenesis II. When milk takes longer to transition from colostrum (the thick, yellow first milk) to mature milk, it can sometimes lead to a lower overall supply if not managed with early support.

The Generational Gap: Perceived vs. Actual Supply

When looking at your family history, it is important to distinguish between a biological inability to make milk and a lack of support. In many cases, what our mothers or grandmothers called "low supply" was actually a result of the common parenting advice of their time.

The Impact of Scheduled Feedings

In previous decades, parents were often told to feed their babies on a strict schedule, such as every four hours. We now know that breastfeeding works on a system of "supply and demand." The more often a baby nurses or a parent pumps, the more milk the body makes. By following a rigid schedule instead of the baby’s hunger cues, many parents in previous generations accidentally signaled their bodies to slow down milk production.

Early Introduction of Supplements

Years ago, it was common practice to supplement with formula or even water very early in the infant's life. When a baby receives a bottle, they spend less time at the breast. This lack of stimulation tells the brain that less milk is needed. Over time, this causes the supply to drop. If your mother experienced this, she might have truly had a low supply, but it was likely caused by these practices rather than her genetics.

Lack of Professional Support

The field of lactation science has grown significantly in recent years. Many women in the past did not have access to an International Board Certified Lactation Consultant (IBCLC). Without help for issues like a poor latch or a tongue-tie, breastfeeding can become painful and inefficient. Pain can inhibit the let-down reflex, and an inefficient latch means the breast is never fully emptied, leading to a permanent drop in supply. For structured education about latch, feeding cues, and milk supply, consider a Breastfeeding 101 course.

Check the latch: Is it comfortable? If not, seek help.
Feed on demand: Watch for rooting, sucking on hands, or smacking lips.
Skin-to-skin: Spend time holding your baby against your bare chest to boost oxytocin.
Empty the breast: Frequent and effective milk removal is the best way to signal more production.

Signs of True Low Milk Supply

It is very common for parents to feel like they have a low supply when their supply is actually perfectly normal. Because you cannot see how many ounces a baby is getting from the breast, you have to look for other clues. This guide to signs of genuinely low milk supply can help you know when further evaluation may be appropriate.

Indicators of a Healthy Supply

If your baby is doing the following, your supply is likely right where it needs to be:

Weight gain: Your baby is following their own growth curve on a pediatric chart.
Diapers: Your baby has at least 6 wet diapers and 3 or more dirty diapers every 24 hours (after the first week).
Alertness: Your baby is active and alert when awake.
Swallowing: You can hear or see rhythmic swallowing during a feeding.

Signs That Need Investigation

If you notice these signs, it is time to talk to a lactation professional or your pediatrician:

Slow weight gain: The baby is not regaining birth weight by two weeks or is dropping off their growth curve.
Lethargy: The baby is too sleepy to wake up for feedings or seems very weak.
Low output: Fewer than 6 wet diapers a day after the first week.
Urate crystals: "Brick dust" or reddish-orange staining in the diaper, which can be a sign of dehydration.

Overcoming Genetic Challenges

Even if you do have a genetic predisposition toward a lower milk supply, it does not mean your breastfeeding journey is over. There are many ways to support your body and maximize the milk you can produce.

The Importance of Early Intervention

If you know you have a family history of low supply or a condition like PCOS, start your support system early. Meet with a lactation consultant before the baby arrives. They can help you create a plan for the first few days of life, which are the most critical for "priming" your milk-making cells.

Power Pumping

Power pumping is a technique designed to mimic a baby’s "cluster feeding." Cluster feeding is when a baby wants to nurse very frequently for a few hours. This usually happens in the evening and is the baby's way of telling the body to make more milk for the next day. To power pump, you pump for 20 minutes, rest for 10, pump for 10, rest for 10, and pump for 10. Doing this once a day for a few days can help signal your body to increase production.

Nutrition and Hydration

While diet alone won't fix a major medical issue, your body needs fuel to make milk. Lactation requires an extra 300 to 500 calories a day. Focus on nutrient-dense foods and staying hydrated.

Many parents find success by adding galactagogues to their diet. A galactagogue is a natural substance that may support or increase milk production. Common examples include oats, brewer’s yeast, and flaxseed. Our Emergency Brownies are a favorite for many moms because they contain these supportive ingredients in a delicious, easy-to-eat treat. If you prefer a refreshing drink, our Pumpin Punch™ or Lactation LeMOOnade™ can help you stay hydrated while providing lactation-supportive ingredients.

Important Note: These products are intended to support general wellness and lactation. This product is not intended to diagnose, treat, cure, or prevent any disease. Consult with your healthcare provider for medical advice before starting any new herbal supplement.

The Mental Load of Low Supply

The stress of worrying about milk supply can actually make the problem worse. When you are stressed, your body produces cortisol. Cortisol can interfere with oxytocin, the hormone you need for your milk to flow.

It is important to remember that your worth as a parent is not measured in ounces. Every drop of breast milk you provide contains valuable antibodies, hormones, and nutrients. Even if you need to supplement with formula or donor milk, the milk you do provide is making a difference for your baby.

We often say at Milky Mama, "Every drop counts." Whether you are exclusively breastfeeding, combo-feeding, or pumping, you are doing an amazing job. Taking care of your mental health is just as important as taking care of your physical milk supply.

Practical Steps to Take Now

If you are currently worried about your supply, here is a simple action plan:

Remove milk more often: If you are nursing, add a pumping session. If you are pumping, add a session or try power pumping.
Check your pump parts: Make sure your valves and membranes are fresh. Ensure your flange (the plastic shield) is the correct size for your nipple.
Hydrate and eat: Keep a water bottle and a snack, like a Milky Mama lactation cookie, nearby during every feeding.
Seek professional help: Don't wait until you are in a crisis. A virtual lactation consultation can provide personalized advice tailored to your specific situation.
Rest: This is hard with a newborn, but sleep is vital for hormone regulation. Try to nap when the baby naps at least once a day.

Conclusion

Is low milk supply hereditary? The answer is a nuanced "yes, but." While genetics and inherited medical conditions can influence your baseline milk production, they are only one piece of the puzzle. Factors like early support, frequent milk removal, and proper nutrition play a massive role in your success.

Remember that even with a genetic predisposition, many parents find they can still meet their breastfeeding goals with the right tools and support. You don't have to navigate this alone.

Genetics can influence milk-making tissue and gene expression.
Hereditary conditions like PCOS and thyroid issues can impact hormones.
Many "hereditary" supply issues in the past were actually due to poor support and outdated advice.
Early intervention and consistent milk removal are key to maximizing supply.

If you feel like your genetics are working against you, remember that we are here to support you. You are more than your DNA, and with the right resources, you can nourish your baby and yourself through this journey.

FAQ

If my mom couldn't breastfeed, does that mean I won't be able to?

Not necessarily. Many parents in previous generations were given advice that accidentally lowered their supply, such as feeding on a strict schedule or supplementing too early. While some medical conditions that affect supply are hereditary, with modern lactation support and updated knowledge, many people are able to breastfeed successfully even if their mothers could not.

What are the main genes that affect milk supply?

Recent research has identified the MFGE8 gene as a significant factor in milk secretion. Other studies have found that genes like PLIN4 and GLP1R may be more active in those with lower supply, while KLF10 is often more active in high producers. These genes influence how mammary tissue develops and how milk is released.

Can I increase my supply if I have a genetic predisposition for low milk?

Yes, in many cases you can. Frequent and effective milk removal through nursing or pumping is the most powerful way to signal your body to make more milk. Supporting your body with proper hydration, nutrition, and stress management can also help you reach your maximum biological potential for milk production. If you are considering a supplement, Lady Leche™ is one option to discuss with your healthcare provider.

Should I get genetic testing for low milk supply?

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Is Low Milk Supply Hereditary? Genetics and Your Breastfeeding Journey

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