<unk>  (contracted from endogenous morphine) are endogenous opioid neuropeptides and peptide hormones in humans and other animals. They are produced and stored in the pituitary gland. The classification of molecules as<unk>  is based on their pharmacological activity, as opposed to a specific chemical formulation. The<unk> class consists of α-endorphin, β-endorphin, and γ-endorphin. All three preferentially bind to μ-opioid receptors. The principal function of<unk>  is to inhibit the communication of pain signals.<unk>  may also produce a feeling of euphoria very similar to that produced by other opioids.
Endorphins
Serotonin
N-Acetylserotonin
Opioid peptide
Gluten exorphin
Neuropeptide
Dynorphin
Beta-Endorphin