Research into human breast milk production has made limited progress compared to other areas of biology, with significant gaps remaining in understanding how lactation works at the cellular and hormonal levels. Scientists are increasingly focused on addressing these uncertainties as they seek to improve knowledge about milk composition, production mechanisms, and potential therapeutic interventions.

Dr. Kelly Twigger, leading a research team at the University of Cambridge, began collecting and analyzing milk samples in early 2025 to study lactocytes—specialized cells in the mammary glands responsible for milk secretion. Her approach involves obtaining fresh milk samples from more than 150 women, with some visits spanning months, to isolate viable lactocytes capable of producing milk in laboratory settings. Twigger emphasizes that previous studies often relied on frozen milk samples, which diminished cell viability and obscured the dynamic nature of milk composition. She finds that milk content varies substantially depending on timing, with fluctuations in antibodies, fats, and water reflecting an infant’s evolving needs.

Twigger’s preliminary work has identified two distinct types of lactocytes seemingly responsible for synthesizing different milk components, but many questions remain. The proportion of milk constituents derived from blood versus mammary synthesis, the long-term impacts of immune cells present in colostrum, and mechanisms governing infant appetite regulation are among the unknowns. Supported by government funding for seven years, her team plans to investigate how diet, medication, and genetics influence milk production. Twigger notes that while breast cancer research has advanced, the study of lactation itself has lagged behind, partly due to historic gender biases in biomedical research.

At the University of Oxford, Dr. Fadil Hannan is conducting complementary investigations on the hormonal regulation of lactation. His research focuses on hormones such as prolactin, critical to stimulating milk production, and cortisol, a stress hormone that may play a supporting role. Hannan highlights that the transition of the breast from an inactive state to a full milk-producing organ within 72 hours postpartum remains poorly understood, despite known hormonal drivers. He and his team have examined how the mammary gland accesses nutrients, including fats and amino acids, and whether it signals body fat or muscle tissue to release these resources.

Hannan’s study has involved over 600 women at the John Radcliffe Hospital, who provided samples of colostrum, milk, and blood. Recent publications from the group have shed light on factors delaying milk production, such as insulin resistance, and validated the importance of certain hormones previously studied only in rodents. Despite these advances, Hannan stresses a persistent gap between scientific findings and clinical practice in the National Health Service, citing insufficient knowledge translation and limited treatment options for low milk supply. Traditional remedies like fenugreek have equivocal evidence, and although domperidone can boost prolactin levels, its optimal dosing for lactation support remains unclear.

The challenges of breastfeeding are compounded by declining professional support. Midwives and health visitors, once primary sources of breastfeeding expertise, have seen their numbers reduce significantly in recent years—health visitor staffing in England, for example, has dropped by 45 percent since 2016. A recent report on maternity care in England highlighted the erosion of postnatal community support services. Professional voices recall a time when healthcare providers worked closely with communities in local settings to offer guidance, a model now diminished by workforce cuts and changing healthcare structures.

Together, these research efforts underscore a critical need for increased investment and integration of lactation science into healthcare to better support mothers and infants during breastfeeding. While progress has been made, experts call for bridging the divide between laboratory discoveries and tangible clinical improvements that address the multifaceted challenges of milk production and lactation support.