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High milk supply (or oversupply) is considered to be present when mum’s breasts are consistently making more milk than is required to meet baby’s nutritional needs. This can lead to blocked ducts and mastitis for mum and might affect baby’s ability to latch and feed comfortably. Some signs of high supply can be normal in the early weeks as breastfeeding is being established, but persistent over supply can cause significant disruption to breastfeeding and should be addressed.

We have previously discussed the issue of milk supply, check out our Understanding Low Milk Supply blog post to read more.

In this article we will explore the signs, causes and management options for dealing with oversupply. 



  • Baby is pulling away from the breast and choking or spluttering when feeding (this can be a sign of fast let-down, which sometimes goes hand in hand with oversupply, however it can also be a sign that baby has reflux).
  • Breasts leak a lot, and often.
  • Getting recurring blocked ducts or mastitis.
  • Breasts regularly feeling overfull and distended, causing pain.
  • Baby is windy and/or has green/forthy, stools, bowel movements are often explosive.
  • Baby might be fussy or upset during and after feeds, arching back and/or crying.
  • Baby can clamp down on the nipple in response to fast flow/high milk volumes, leading to nipple pain.
  • Nipple blebs or ‘milk blisters’ can sometimes coincide with high supply and blocked ducts.

Oversupply can be difficult to manage, and sometimes signs of having too much milk mask signs that baby is struggling with feed coordination. Reach out to a lactation professional to assess your feeding if you notice any of the above signs.



Similarly to what we discussed in our post on Understanding Low Milk Supply, causes for oversupply can be behavioural or physiological. This means that breastfeeding practices or patterns may be the cause of oversupply, or it could be related to mum’s physiology. Certain medications may also affect milk supply, discuss these with your doctor and lactation consultant before ceasing use of any prescribed medications.

The prevalence of high milk supply is not well researched, so it is difficult to say how many women this condition might affect. Similar to what we discussed in the low milk supply article, this area requires more and better research.


Breast milk supply is established in the first few weeks after birth. As baby stimulates and empties the breast, breasts learn how much milk baby needs. Some breastfeeding behaviours can lead to too much milk being produced, below is a list of the most common practices that cause oversupply:

  • Trying to implement a feeding ‘routine’, this can disrupt on-demand feeding and can sometimes lead to oversupply.
  • Pumping on top of on-demand feeding. Milk that is removed from the breast will be replaced. Pumping increases the amount of milk removed from breasts, therefore more milk is produced to replace it.
  • Switching baby to the second breast before they have come off the first breast themselves, or stopping a feed before baby is finished. These practices can mean baby is receiving mostly low fat foremilk which may make them hungry again sooner. Interrupting on-demand feeding in this way can lead to increased feed frequencies and high supply.
  • Using substances for increasing milk production unnecessarily and without appropriate guidance from a health professional, these can include galactagogues.

Some women naturally make a lot of milk and have high milk storage capacities. Women with a high supply due to physiological reasons will notice that signs persist beyond 4-6 weeks after birth and behavioural changes have little effect. They are also more likely to experience recurring blocked ducts and/or mastitis. Our understanding for this is limited but below are some physiological factors that may lead to high supply:

  • Pituitary disorders.
  • Thyroid disorders, most likely hyperthyroidism.
  • Polycystic Ovary Syndrome (PCOS).



Breastfeeding can take a few weeks to become established and mums often find these issues settle after 3-4 weeks, this can take longer if baby was born early. 

If you are struggling with symptoms of high milk supply, reach out to a lactation consultant. They can support you with techniques to help manage your high supply, below are some examples:

  1. Try block feeding, feeding from one breast only for 3 hour blocks. Start by emptying both breasts fully, through breastfeeding/pumping. Then begin the block feed pattern: feed from the left breast only for 3 hours, then switch to the right for the following 3. Repeat this pattern throughout the day, and if preferred feed as you normally would at night. If you find the opposite breast baby is feeding from feels very full and painful, express a little, but only enough to make you comfortable.
  2. You can also try to keep your breasts at least 1/3 full at all times, consistently for a few days. Without emptying either breast, the feedback to produce more milk should reduce. It is still important that baby feeds until they come off the breast themselves, so this one can be tricky.
  3. Express a small amount of milk before baby latches. This can be particularly effective when fast let-down causes baby to choke or splutter at the breast, as it relieves some of the pressure. It can help create a calmer breastfeed that may encourage baby to feed for longer, having a positive knock-on effect on supply.
  4. Try different breastfeeding positions. Try leaning back and allowing baby to latch from different angles (i.e. if baby often nurses in cross cradle, try the side hold/rugby ball positon, or try laying baby across your chest so they can attach from above the nipple). This will encourage improved draining of more areas of the breast. It can be helpful when clearing blocked ducts to try positioning baby’s chin to indent the affected area.

Physiologically high supply may not be entirely fixed by behavioural methods, but they can be useful to manage the symptoms. If your high supply persists beyond 4 weeks post birth, or is causing significant problems, reach out to a lactation consultant. They may refer you to another health professional for further exploration and potentially pharmacological management of your supply.



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Mitchell, K. B., & Johnson, H. M. (2020). Breast Pathology That Contributes to Dysfunction of Human Lactation: a Spotlight on Nipple Blebs. Journal of Mammary Gland Biology and Neoplasia, 25(2), 79-83. 

Smillie, C. M., Campbell, S. H., & Iwinski, S. (2005). Hyperlactation: How Left-brained ‘Rules’ for Breastfeeding Can Wreak Havoc With a Natural Process. Newborn and Infant Nursing Reviews, 5(1), 49-58.

Spencer, K. W. a. B. (2021). Breastfeeding and Human Lactation (6th ed.). Jones and Bartlett Learning

Trimeloni, L., & Spencer, J. P. (2016). Diagnosis and Management of Breast Milk Oversupply. The Journal of the American Board of Family Medicine, 29, 139 – 142.