Defining Low Supply

The Basics

Primary low supply is related to the capacity of the lactating parent’s body. Some things that might limit the potential for milk production are hormones, insulin resistance, or not having enough breast tissue (this is often referred to as insufficient glandular tissue or IGT). Secondary low supply results from non-ideal breastfeeding management and other factors that limit how much milk the baby can remove. It occurs in cases when someone is physiologically capable of making a full milk supply in ideal conditions. As the authors of Making More Milk say, “You start with the capacity to make a full supply, but something happens to reduce how much milk is made” (Marasco & West, 2019, p. xv). Perceived low supply is a feeling that there isn’t enough milk for the baby. Chronic low milk supply can be either primary or secondary low milk supply, if it lasts for the entire breastfeeding relationship despite ideal breastfeeding management.

Full Definitions with Citations

Primary low milk supply or primary lactation insufficiency is due to intrinsic factors (Marasco & West, 2019) such as hormonal imbalance (Whelan et al., 2025), metabolic disease (Whelan et al., 2025), or insufficient glandular tissue (also called “primary glandular insufficiency”; Niefert et al., 1985; Whelan et al., 2025; Kellams et al., 2017). Some authors include breast surgeries or procedures in the definition of primary low milk supply (Batterjee & Zedan, 2025).

Secondary low milk supply or secondary lactation insufficiency is due to suboptimal breastfeeding management or factors extrinsic to the lactating parent (Whelan et al., 2024). These extrinsic or external (Marasco & West, 2019) factors result in less milk being removed than is physiologically normal and include (but are not limited to) infant oral-motor function or anatomical variations, infant disorders affecting feeding, and endocrine-disrupting chemicals (Jin et al., 2024), as well as medical conditions related to pregnancy and labor (e.g., retained placenta, hemorrhage, or Sheehan Syndrome; Batterjee & Zedan, 2025). Some authors list breast surgeries and procedures as extrinsic reasons for low supply (Jin et al., 2024; Manshanden et al., 2025).

Perceived low milk supply or perceived insufficient milk supply is characterized by feelings that milk supply is not adequate to meet the baby’s needs (Hill & Humenick, 1989; Huang et al., 2022), often in the absence of “actual” insufficient milk production (Galipeau et al., 2017).

Chronic low milk supply or chronic lactation insufficiency can refer to low supply from both extrinsic and intrinsic causes, when that low supply continues for the duration of the breastfeeding relationship despite adherence to best practices in breastfeeding management (Scott et al., 2025; Shere et al., 2021).

References

Marasco, L., & West, D. (2019). Making more milk: The breastfeeding guide to increasing your milk production (2nd ed.). McGraw‑Hill Education.

Neifert, M. R., Seacat, J. M., & Jobe, W. E. (1985). Lactation failure due to insufficient glandular development of the breast. Pediatrics, 76(5), 823–828. https://doi.org/10.1542/peds.76.5.823

Whelan, C., O’Brien, D., & Hyde, A. (2025). Breastfeeding with primary low milk supply: A phenomenological exploration of mothers’ lived experiences of postnatal breastfeeding support. International Breastfeeding Journal, 20(7). https://doi.org/10.1186/s13006-025-00699-4

Kellams, A. L., Harrel, C., Omage, S., Gregory, C., Rosen‑Carole, C., & Academy of Breastfeeding Medicine. (2017). ABM clinical protocol #3: Supplementation of the breastfeeding infant (3rd ed.). https://abm.memberclicks.net/assets/DOCUMENTS/PROTOCOLS/3-supplementation-protocol-english.pdf

Whelan, C., O’Brien, D., & Hyde, A. (2024). Mother’s emotional experiences of breastfeeding with primary low milk supply in the first four months postpartum: An interpretative phenomenological analysis. Breastfeeding Medicine, 19(3), 197–207. https://journals.sagepub.com/doi/epub/10.1089/bfm.2023.0231

Jin, X., Perrella, S. L., Lai, C. T., Taylor, N. L., & Geddes, D. T. (2024). Causes of low milk supply: The roles of estrogens, progesterone, and related external factors. Advances in Nutrition, 15(1), Article 100129. https://www.sciencedirect.com/science/article/pii/S216183132301390X?via%3Dihub

Batterjee, M., & Zedan, H. (2025). Distinguishing between lactation failure and breastfeeding cessation: A scoping review. Breastfeeding Medicine, 20(1), 5–18. https://doi.org/10.1089/bfm.2024.0265

Manshanden, T. M. N., Abelha, S. G., Velzel, J., McEachran, J. L., Geddes, D. T., & Perrella, S. L. (2025). Characteristics and experiences of lactating women with measured low milk production. International Breastfeeding Journal, 20, 64. https://doi.org/10.1186/s13006-025-00753-1

Hill, P. D., & Humenick, S. S. (1989). Insufficient milk supply. Image: The Journal of Nursing Scholarship, 21(3), 145–148. https://www.researchgate.net/publication/20482221_Insufficient_Milk_Supply

Huang, X., Liu, Y., Yu, C., & Zeng, L. (2022). The rates and factors of perceived insufficient milk supply: A systematic review. Maternal & Child Nutrition, 18(1), e13255. https://doi.org/10.1111/mcn.13255

Galipeau, R., Dumas, L., & Lepage, M. (2017). Perception of not having enough milk and actual milk production of first-time breastfeeding mothers: Is there a difference? Breastfeeding Medicine, 12(4), 210–217. https://doi.org/10.1089/bfm.2016.0183

Scott, S. F., Searcy, J., & Jordan, I. (2025). “Why is there not a doctor that knows anything about this part of my body?” Patient perspectives on chronic lactation insufficiency. Breastfeeding Medicine, 20(8), 554–559. https://doi.org/10.1089/bfm.2025.0018

Shere, H., Weijer, L., Dashnow, H., Moreno, L. E., Foxworthy Scott, S., & Baker, H. (2021). Chronic lactation insufficiency is a public health issue: Commentary on “We need patient-centered research in breastfeeding medicine” by Stuebe. Breastfeeding Medicine, 16(12), 933–934. https://doi.org/10.1089/bfm.2021.0202