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Endorphins facts for kids

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Drawing of an endorphin

Endorphins are natural chemicals in the body that fight pain. Endorphins are released when a person gets hurt, but also during exercise or laughter. In addition to blocking pain, endorphins can make people happy.

Endorphins resemble drugs like morphine, so when scientists first discovered these chemicals in the 1970s, they termed them "endogenous morphine." Since then, scientists have identified and named five different types of endorphins, all of which occur naturally in the body. Endorphins can also be found in most animals.


Four types of endorphins are created in the human body. They are named alpha (α), beta (β), gamma (γ) and sigma (σ) endorphins. The four types have different numbers and types of amino acids in their molecules; they have between 16 and 31 amino acids in each molecule.

Beta-endorphins (β-endorphins) are the most powerful endorphins in the body. They are usually in the hypothalamus and pituitary gland. More endorphins are released in the pituitary gland during times of pain or stress. Exercise increases the endorphin release too. For the same reason, exercise results in a better mood.

Met-enkephalin and leu-enkephalin are in the brain stem and spinal cord; they are the pain killers of the spinal cord. Both of them have five amino acids in their structure; the first four are similar, but the last one is different.


All of the endorphins bind to the opioid receptors in the brain. Many of the analgesic (pain killer) drugs have a similar action in the brain. The main difference between the natural endorphins and the analgesic drugs is that natural endorphins are cleared from the blood very quickly. Also, scientists think that acupuncture results in the release of more endorphins. Endorphins may have a role in obesity, diabetes and psychiatric diseases too.

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