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How Long Does It Take for Dairy to Leave Breast Milk?

How Long Does It Take for Dairy to Leave Breast Milk?

Cow’s milk protein in breast milk peaks at 2 hours and is undetectable at 6 hours.

Knowing this information can help identify and prepare moms if their baby is sensitive to dairy.

Here are some handy key points in this article:

  • Cow’s milk protein intolerance (CMPI) is different from lactose intolerance.
  • Symptoms of dairy sensitivity in babies include gas, fussiness, diarrhea, vomiting, or eczema. It can occur after babies are breastfed. 
  • It’s safe to continue breastfeeding while eliminating dairy.
  • Soy and almond milk are among the dairy alternatives.

I have included all the information you’ll need in this article. 
NOTE: If your motherly instincts say your baby may be sensitive to dairy, I highly suggest talking to a doctor or lactation consultant.

How Long Does It Take for Dairy to Leave Breast Milk?

How Long Does It Take for Dairy to Leave Breast Milk?

A study from Frontiers in Nutrition suggests cow’s milk protein peaks in breast milk at 2 hours post-ingestion and is undetectable at 6 hours.

This means mothers trying to avoid cow’s milk dairy should wait 6 hours after consumption before breastfeeding.

When a breastfeeding mother is advised to cut down on certain foods, it is typically due to protein content (CMPI) concerns rather than lactose intolerance.

A guideline from the National Library of Medicine suggests a 3-6 day elimination diet for immediate reactions to cow’s milk protein.

Thus, the diet may need to be continued for up to 14 days for delayed reactions. If there is no improvement, other diagnoses should be considered.

A lactation massage may not affect dairy clearance, but it can support breastfeeding health and ease the transition to a dairy-free diet.

How Long Does Dairy Stay in Your Baby’s System?

Although proteins from cow’s milk clears from breast milk within a day, the reaction in a baby’s gut can last for days to weeks.

This is because the baby’s immune system may have already been exposed to the protein and developed an allergy or intolerance.

The residual inflammation from the protein exposure causes the reaction to persist. Not the continual exposure to your breastmilk.

If your baby has cow’s milk protein intolerance (CMPI), they may experience colic-like symptoms. Babies may also experience wheezing, vomiting, diarrhea, constipation, rash, or eczema.

A dairy allergy can lead to reduced milk production in one breast as the proteins from dairy can enter the breast and trigger an allergic response in the baby.

Should I Cut Dairy Out When Breastfeeding?

You may have to follow a dairy-free diet if your baby shows symptoms of a dairy allergy or intolerance — or on your doctor’s advice.

This is because the proteins in cow’s milk can pass through breast milk and cause a reaction in your baby’s gut. After all, your diet will affect your breast milk.

Nonetheless, it is safe to continue breastfeeding while eliminating dairy, as the protein clears from your milk within 6 hours.  

If you cut out dairy, ensure that you still get protein from other sources, such as dark leafy greens, broccoli, and fortified cereals.

Tips for a Dairy-Free Diet While Breastfeeding

Tips for a Dairy-Free Diet While Breastfeeding

If you’re eliminating dairy from your diet while breastfeeding, whether to increase milk supply or for your baby’s allergies, here are some tips from expert moms to guide you:

1. Understand What Dairy Is

Dairy does not just mean milk or liquid white drinks. 

It can also refer to solid foods made from milk, such as cheese, yogurt, and butter, among others.

Additionally, many hidden dairy sources exist in processed foods, such as whey, casein, and lactose.

Dairy products are good protein, calcium, and other nutrient sources. However, some babies may be allergic or intolerant to these dairy products.

2. Read Labels Carefully

Many processed foods contain dairy ingredients not always listed on the label. 

This can confuse moms on a dairy-free diet, as they may not realize they already consume dairy products.

You must read labels carefully and get familiar with these ingredients, as these are related to milk:

  • Whey
  • Casein
  • Lactose
  • Nonfat milk
  • Skim milk
  • Reduced-fat milk
  • Whole milk
  • Caseinates
  • Lactalbumin
  • Lactose solids
  • Lactose monohydrate
  • Lactose powder
  • Rennet
  • Rennet casein
  • Rennet extract

There are less common terms, like lactose-free, milk derivatives, and may contain milk that you should also watch out for. 

These terms may indicate dairy content, so remember to ask around. That leads me to my next tip.

3. Don’t Be Afraid to Ask

Asking questions from fellow moms is important for a dairy-free diet while breastfeeding.

Expert moms who have gone through a similar journey can provide valuable insights, tips, and advice based on their experience. 

Other moms and doctors are more than willing to help you, even with your lactation concerns like “Does breast milk differ between breasts?” or “Can breast milk come back after drying up?

Besides asking your mom friends, you can also inquire about specific food preparation or manufacturing ingredients. 

This helps you determine if any hidden dairy sources might be present, even if they are not clearly listed on the label.

4. Give It Time

Give it at least a month to see improvement in your baby’s reaction to your milk after eliminating dairy. 

You may also consider cutting out soy for the first four weeks, as soy and milk proteins can have similar effects. 

Take a gradual approach when eliminating dairy to avoid feeling overwhelmed and reduce the risk of slip-ups.

Start by cutting out one or two dairy products at a time, and monitor your baby’s reaction.

5. Find Good Substitutes for Dairy Products

Discovering suitable alternatives for dairy products is the last tip I learned from expert moms and parenting seminars I’ve been to.

You can check these foods as dairy substitutes:

  • Plant-based/Non-dairy milk – Almond milk, coconut milk, oat milk, soy milk, and rice milk
  • Non-dairy yogurt options – Coconut yogurt, almond yogurt, soy yogurt
  • Cheese replacements – Nut-based, soy-based, coconut milk-based cheeses
  • Butter alternatives – Coconut oil, olive oil, avocado oil
  • Dessert swaps – Vegan ice cream, dairy-free chocolate or carob chips, homemade treats

Adequate protein intake is crucial for milk production during breastfeeding, particularly in cases where you aren’t producing milk after delivery.

Instead of milk protein, you can have green leafy vegetables, tofu, salmon, beans, or eggs. These foods can help increase milk supply and provide you with essential nutrients.

Frequently Asked Questions

Thanks to the valuable insights from parenting seminars and experienced moms, I have compiled these FAQs. 

Before concluding, let me address these lingering questions about dairy-free diets, dairy allergies, and alternative options.

How Long Will I Need to Avoid Dairy?

If your baby has a dairy allergy, you will be prescribed to refrain from consuming dairy for 2-4 weeks to observe if the symptoms subside.

However, if your baby only has a dairy intolerance, you can go back to having dairy after a few weeks.

Combining hand expressed-milk with bottle feeding allows you to switch to a dairy-free formula. 

Many dairy-free formulas and supplements like moringa suit your baby’s preferences and needs. It is important to consult a doctor to determine the appropriate duration of dairy avoidance.

What Is the Difference Between a Dairy Allergy and Lactose Intolerance?

Lactose intolerance is not life-threatening, but a milk allergy can be.

A dairy allergy occurs when the immune system reacts to milk proteins. It can cause hives, swelling, itching, breathing issues, vomiting, and diarrhea.

Lactose intolerance is a digestive problem caused by inadequate lactase enzyme production. It results in symptoms like bloating, gas, diarrhea, and cramps.

Lactose intolerance means the body has trouble digesting milk sugar. Milk allergy is when the body’s immune system reacts to milk proteins.

Will My Baby Outgrow a Milk Protein Allergy?

Most children will outgrow cows’ milk protein allergies by 3-5, but some may not.

While it is rare for the allergy to persist into adulthood, in some cases, symptoms may continue. Younger children with milk allergies are more likely to outgrow them than those who develop allergies at an older age.

NOTE: Early diagnosis can help prevent your baby from having severe allergic reactions to medications like Benadryl and ensure proper nutrition.


Your pediatrician may recommend cutting out dairy from your diet if your baby shows signs of CMPI, as the proteins can cause adverse reactions in the baby’s gut.

When considering its impact on breastfeeding moms and their babies, start with understanding what dairy is. Look into lactation supplements and how they can help you, too.

Seeking information, following medical advice, and finding support help a dairy-free breastfeeding journey.

Nayna Llenos
Nayna Llenos

Hi, I’m Nayna!
I’ve always wanted to be a mother, and I’m lucky and blessed to have two wonderful children to care for and love.
Despite this blessing, there are times wherein I do wonder if I truly am the mother my children need. Am I giving them the right food, care, and discipline to them?
But that is the beauty of parenting — you grow along with your children as they flourish to be their wonderful selves!
I wish to share my experiences with motherhood and how these tips can help you in your parenting journey.
I hope my advices and experiences will prove useful to you and that you have a smooth and wonderful journey as a mother!