What is an Endorphin?

An endorphin is a natural pain reliever produced by the body in response to a number of factors. It binds to the parts of the nervous system that bind to morphine, relieving pain and frequently producing a natural high. In contrast to the effects of narcotics, endorphin activity is not addictive. A runner’s high is one response that is thought to be due to the effects of endorphins.

There are a number of endorphins produced by humans. They are neurotransmitters, meaning they transmit signals throughout the nervous system and are found in the brain — specifically in the pituitary gland. A receptor is a molecule that transmits signals, and an endorphin binds to a receptor that morphine and other opiates gravitate to. It is known as an opiate receptor.

Endorphins are released when a pain signal reaches the spinal cord/ It prevents more pain signals from being released from the nerve cells. Although the primary activity of endorphins is to relieve pain, they can also trigger feelings of euphoria, such as the release of sexual hormones. Many things can cause an endorphin response. Enjoyable things like sex, massage, and acupuncture can trigger the production of endorphins. Stress and low levels of pain can also cause an endorphin response.

The active compound in chili peppers stimulates this response also, and is used as a topical pain reliever. Some people eat very hot peppers to get a feeling of pleasure, as the stronger chili peppers cause more endorphins to be produced. It appears that the runner’s high obtained after intense, prolonged activity is due, at least partly, to the activity of endorphins, although there has been some controversy about this. There can be a downside to these exercise endorphins that reduce perceived pain, because some people push past their level of endurance, and can injure themselves during exercise or sports.

During pregnancy, part of the placental tissue excretes endorphins into the mother’s blood. After birth, breast-feeding can stimulate endorphin production. The latter process is thought to help prevent postpartum depression.

The term endorphin comes from a combination of the word endogenous, meaning 'from within the organism,' and orphin, derived from 'morphine.' There are a number of endorphins, but they all bind an opiate receptor. The major types of endorphins are beta-endorphin, which is found in the pituitary gland, and dynorphin and enkephalins, which are found throughout the nervous system.

Endorphins are peptides, which are small chains of amino acids. Technically, they are known as endogenous opioid polypeptides. Polypeptides are slightly larger peptides, and many of them are biologically active.