Researchers at the University of Oklahoma learned that a naturally made hormone can shrink body fat in mice. The hormone talks to a special part of the brain that controls how we burn energy and feel hungry.
This hormone is called FGF21, short for fibroblast growth factor 21. Scientists are already testing medicines that act like FGF21 for a serious liver condition called MASH.
Lead scientist Matthew Potthoff and his team wanted to know exactly where in the brain FGF21 works. They discovered that the hormone sends its message to the hindbrain, which sits at the back of the head.
Surprising Brain Spot"We first thought FGF21 would talk to the hypothalamus, a region many weight‑control studies focus on," Potthoff explained. "Instead, we found the signal goes to the hindbrain, the same area where popular GLP‑1 weight‑loss drugs act."
In the hindbrain, FGF21 connects with two tiny zones: the nucleus of the solitary tract (NTS) and the area postrema (AP). These areas then pass the signal to another structure called the parabrachial nucleus. This chain is key for the hormone’s ability to boost metabolism and lower weight.
Brain Circuit Helps Burn FatPotthoff said, "Understanding this circuit could help us design medicines that work well without causing stomach upset or bone loss, side effects seen with some FGF21‑based drugs."
While both FGF21 and GLP‑1 drugs affect the hindbrain, they act differently. GLP‑1 medicines mainly curb appetite, whereas FGF21 raises the body's energy use, helping it burn more calories.
Hope for Future TreatmentsThe team believes this discovery could lead to new, safer treatments for obesity and for MASH. More studies are needed to see if the same brain pathway also helps reverse liver disease.