Does Chlorine Affect Milk Supply? Debunking Myths for Breastfeeding Moms

December 15, 2025 •

4 min read

While chlorine can cause dry and cracked skin, it is not known to directly affect breast milk, milk supply, or lactation in any way. This common concern among new parents regarding whether chlorine affects milk supply can be addressed with an understanding of different exposure types.

Quick Summary

Chlorine exposure from swimming doesn't harm milk supply, but skin dryness can cause discomfort that may lead to infrequent feeding, potentially impacting production. Staying well-hydrated is paramount, and filtering tap water reduces disinfection byproducts.

Key Points

No Direct Impact: Chlorine from swimming pools does not directly affect breast milk or lactation.
Indirect Effects Exist: Dehydration and skin dryness from chlorine exposure can indirectly impact milk supply by reducing feeding frequency.
Tap Water Consideration: Chlorine in drinking water can form disinfection byproducts (DBPs) that may pass into breast milk, but low levels are considered safe by EPA.
Hydration is Key: Staying well-hydrated is crucial for maintaining milk supply, especially during exercise or in warm weather.
Simple Precautions: Showering after swimming and using a tap water filter can effectively manage chlorine exposure for breastfeeding mothers.
Nipple Health Matters: Protecting nipples from dryness and cracking caused by chlorine is important for comfortable and consistent breastfeeding.

Understanding Chlorine Exposure for Breastfeeding Moms

For many new parents, questions arise about resuming normal activities, including swimming in chlorinated pools. A core concern is the potential impact of chemicals like chlorine on a mother's breast milk. The good news is that recreational chlorine exposure from swimming does not directly harm your breast milk or lactation. The chemical is used in pools and public water systems primarily to kill bacteria and prevent the spread of illness. However, indirect effects and other sources of exposure should be considered to support optimal milk production and overall health.

The Real Connection: Dehydration and Skin Health

One of the most significant indirect effects of chlorine exposure relates to dehydration and skin irritation. Excessive exercise or time spent in the sun while swimming can lead to dehydration, which can, in turn, reduce milk supply. Therefore, staying well-hydrated, especially in warmer weather, is a critical factor for any breastfeeding mother. Beyond hydration, chlorine is known for its drying effect on the skin. This can be problematic for breastfeeding mothers, as it can cause dry, cracked, and sore nipples. Nipple discomfort can make breastfeeding or pumping painful, potentially leading to less frequent feedings. Less frequent removal of milk from the breasts signals the body to produce less, resulting in a dip in milk supply over time. To mitigate this risk, it is important to shower and rinse off thoroughly after swimming to remove all traces of chlorine.

Tap Water: Chlorine and Disinfection Byproducts

While swimming pool exposure is generally safe with a few precautions, a different type of chlorine exposure comes from tap water. When chlorine is used to disinfect drinking water, it can react with organic matter to form disinfection byproducts (DBPs). Studies have shown that low levels of these DBPs can pass into breast milk. While the research on the long-term health effects of these low-level DBPs on infants is still growing, potential impacts on thyroid function and other developmental aspects have been suggested. Due to this, some experts recommend filtering tap water as a precautionary measure to minimize a mother's exposure to these byproducts. Investing in a high-quality water filter is one proactive step mothers can take to support their baby's health and reduce potential strain on their detox pathways.

Practical Tips for Breastfeeding and Chlorine Exposure

Following a few simple steps can help breastfeeding moms safely enjoy activities involving chlorine without worry:

Rinse off thoroughly: Shower immediately after swimming to wash all chlorine residue from your skin and hair. This is especially important for the nipple and areola area.
Stay hydrated: Keep a water bottle handy and drink to thirst, especially before and after exercise or sun exposure.
Moisturize: Apply a soothing, breastfeeding-safe nipple balm after showering to counteract the drying effects of chlorine and prevent cracking.
Mind your swimwear: Ensure that your swimsuit and any nursing bras are not too tight, as constrictive clothing can restrict milk flow and contribute to clogged ducts.
Consider water filtration: For added peace of mind, use a filter on your tap water to reduce exposure to disinfection byproducts.
Exit the pool to feed: To avoid your baby swallowing chlorinated water, it's best to exit the pool and rinse yourself off before feeding.

Exposure Comparison: Pools vs. Tap Water

To better understand the differences in exposure, consider the following comparison:


Aspect	Chlorinated Pools	Chlorinated Tap Water
Direct Effect on Milk Supply	No direct effect.	No evidence of direct effect on supply.
Potential Indirect Effects	Can cause skin dryness, leading to nipple soreness and potentially reduced feeding frequency. Risk of dehydration impacting supply.	Low levels of disinfection byproducts (DBPs) can enter breast milk, with potential infant health implications being studied.
Exposure Route	Dermal (skin) absorption and inhalation of vapor.	Oral (ingestion) and potential inhalation/dermal from showers.
Remediation	Shower and rinse off thoroughly after swimming.	Filtering tap water is a preventative measure against DBPs.

Conclusion

In summary, the direct effect of chlorine on milk supply is a common myth that can be confidently debunked. Exposure from swimming pools does not contaminate breast milk or reduce production. However, indirect factors, such as dehydration caused by exercise and sun, and skin irritation leading to nipple discomfort, can negatively impact breastfeeding frequency and, consequently, supply. More nuanced considerations arise from tap water, where disinfection byproducts may be present. For proactive mothers, filtering drinking water is a sensible step. The key takeaway is that with proper hydration and basic post-swim hygiene, breastfeeding mothers can safely enjoy swimming and use public water sources without fearing for their milk supply. For additional support, mothers can consult with healthcare professionals or resources like KellyMom.com, which provides evidence-based information for breastfeeding mothers.

Sources

Muscle Up Mommy. (2024). Swimming While Breastfeeding: What You Should Know.
Kyn & Folk. (2024). Why Filtering Your Tap Water Matters When You're Breastfeeding.
KellyMom. (2023). Can I continue to breastfeed if…? Beauty/Recreation/Misc..
Reddit. (2023). Swimming and breastfeeding?.
Ameda. (2019). Breastfeeding and Breast Pumping in the Summertime.
Centers for Disease Control and Prevention. (2024). About Water Disinfection with Chlorine and Chloramine.
Paloma Health. (2024). Why The Chlorine in Swimming Pools Can Affect Your Thyroid.

Frequently Asked Questions

No, swimming in a chlorinated pool will not directly harm your milk supply. However, dehydration from exercise can cause a temporary dip, so it's important to stay hydrated.

Yes, it is a good idea to take a quick shower or rinse your nipples with fresh water after swimming before nursing. This prevents your baby from ingesting any chlorinated water and helps protect your skin from dryness.

Drinking standard chlorinated tap water is generally considered safe and will not affect your milk supply. The U.S. EPA regulates chlorine levels in drinking water to be safe for human consumption.

DBPs are compounds formed when chlorine reacts with organic matter in water. While some studies show low levels can pass into breast milk, filtering your tap water is a simple precautionary measure to minimize exposure.

The act of exercising itself does not decrease milk production, but dehydration from any physical activity can. Staying well-hydrated is the most important factor in maintaining your supply during and after exercise.

While breast milk itself poses no risk to other swimmers, it is recommended to exit the pool to breastfeed to prevent your baby from swallowing any chlorinated pool water, which can be harmful.

After showering post-swim, apply a breastfeeding-safe nipple balm or a small amount of expressed breast milk to your nipples to help moisturize and protect against dryness caused by chlorine.