Emerging Research on Prolactin's Non-Classical Roles: Implications for Hypoprolactinemia

Prolactin is well-known for its role in lactation and reproduction, but recent studies suggest it also influences neuroprotection, immune modulation, bone health, and metabolic regulation. Hypoprolactinemia, an endocrine disorder marked by low prolactin levels, is linked to pituitary dysfunction and has implications for metabolic, neurological, and immune systems that remain largely unexplored. This review highlights prolactin's non-classical roles in neurogenesis, cognitive function, mood regulation, immune response, and metabolism, discussing potential links to metabolic disorders, neuropsychiatric conditions, and increased infection risk. It also addresses the diagnostic challenges due to variable prolactin levels and the absence of standardized criteria. Possible therapeutic approaches, including prolactin replacement therapy and lifestyle changes, are considered to alleviate the effects of low prolactin. The review emphasizes the need to recognize hypoprolactinemia as a significant condition with diverse physiological impacts and suggests avenues for future research to enhance understanding and improve patient care.