Which substance acts as natural painkillers in the body and is linked to pleasure?

Endorphins are substances produced by the body that function as natural painkillers. They are peptide hormones released in response to stress, pain, and physical exercise, effectively modulating pain perception and enhancing feelings of well-being. Endorphins bind to the brain's opioid receptors, which leads to a reduction in pain and an overall sensation of pleasure, often referred to as the "runner's high." This connection between endorphins, pain relief, and pleasure makes them crucial in both physical and emotional contexts.

Other options like norepinephrine, GABA, and dopamine play different roles in the body's functioning. Norepinephrine is primarily involved in arousal and alertness, GABA functions mainly as an inhibitory neurotransmitter that reduces neuronal excitability, and dopamine is closely associated with the reward system and motivation. While dopamine can also contribute to feelings of pleasure, it does not specifically act as a natural painkiller like endorphins do.