Which system in the human body is responsible for regulating metabolism?

The hormones created and released by the glands in your body’s endocrine system control nearly all the processes in your body. These chemicals help coordinate your body’s functions, from metabolism to growth and development, emotions, mood, sexual function, and even sleep. The endocrine system is made up of organs called glands. Glands produce and release different hormones that target specific things in the body. You have glands all over your body, including in your neck, brain, and reproductive organs. Some glands are tiny, about the size of a grain of rice or a pea. The largest gland is the pancreas, which is about 6 inches long.

Source: Cleveland Clinic