As an endocrinologist with many years of experience, I know staying updated on current research on hormones is important. I want to share current research on kisspeptin and its receptor KISS1R in obesity and reproductive hormones, and whether this could offer a new therapeutic target for PCOS. 

When we think of PCOS, we focus on insulin resistance, hyperandrogenism, and ovulatory dysfunction. But emerging evidence suggests that kisspeptin signalling might be a critical piece of the puzzle we have been overlooking. 

Kisspeptin is a tiny protein in the brain that acts like a master switch for reproduction. It acts via the KISS1R receptor and plays a master regulatory role in the reproductive axis, particularly by controlling GnRH secretion from the hypothalamus. In simple terms, without kisspeptin, the brain cannot properly stimulate the pituitary to release LH and FSH, two hormones essential for normal ovulation and menstrual cycles. 

Recent studies show that kisspeptin does more than just control sex hormones. It’s also active in metabolism and body weight. Kisspeptin and KISS1R are found in the fat tissue, liver and pancreas, suggesting roles in energy balance. 

Emerging evidence indicates that kisspeptin signalling in astrocytes, a type of glial cell in the brain, contributes to reproductive function and its modulation by metabolic status. A 2024 study demonstrated that kisspeptin receptors are expressed in astrocytes, and their activation influences gonadotropic-releasing hormone secretion. This finding reveals a non-neuronal pathway for kisspeptin action, highlighting the complexity of its role in reproductive regulation. 

In a study in 2023, women who were overweight were given an IV infusion of kisspeptin and were carefully measured for their appetite and blood sugar. It showed that kisspeptin did not make them hungrier or raise blood sugar, but it did raise the luteinising hormone strongly. 

What does all this mean for PCOS? PCOS is a common condition in women with irregular periods, excess male hormones and often weight gain. Kisspeptin is often turned up in PCOS. Studies have reported that women with PCOS have higher kisspeptin levels than women without PCOS.

Another study found kisspeptin strongly linked to testosterone and LH, whether the women were obese or not. Due to these findings, researchers suggest kisspeptin as a possible biomarker or treatment target for PCOS. Currently, there are no kisspeptin-based drugs for PCOS specifically.