Discovery: morphine made by the brain
In 1973 Candace Pert and Solomon Snyder at Johns Hopkins showed that the brain contains opiate receptors that morphine binds to. If the body had receptors for a plant drug, researchers reasoned, it must make its own matching chemicals. In 1975 John Hughes and Hans Kosterlitz at the University of Aberdeen isolated the first, enkephalins, from pig brains, and beta-endorphin soon followed. The word endorphin blends "endogenous" and "morphine."
How they work and the runner's high
Endorphins inhibit pain signals traveling through the spinal cord and brain, and they indirectly boost dopamine release in the reward circuit, producing calm and well-being. They help explain why people sometimes feel no pain right after a serious injury, and part of the pain relief from acupuncture and placebos. A 2008 German PET study found increased opioid binding in the brain after a long run, supporting their role in the runner's high. Because blood endorphins cross into the brain poorly, many researchers now think endocannabinoids share the credit.
Boosting them, and myths
Studies link moderate-to-vigorous aerobic exercise, hearty laughter, group singing or dancing, spicy food and massage to endorphin release. These activities support mood alongside serotonin and oxytocin, but there is no trick that raises endorphins alone, and claims about specific "endorphin foods" are mostly marketing. If low mood lasts more than two weeks, it is better to seek help for possible depression than to rely on exercise alone.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- What's the difference between endorphins and dopamine?
- Endorphins are opioid peptides that relieve pain and bring calm, while dopamine is a neurotransmitter tied to motivation and anticipated reward. Endorphins can indirectly increase dopamine, so they often work together.
- How much exercise does it take to get a runner's high?
- It varies, but studies usually report it after 30–60 minutes or more of moderate-to-hard running, and not everyone feels it clearly.
Sources reviewed: 2026-10-26
References
- Hughes, J., Smith, T. W., Kosterlitz, H. W., et al. (1975). Identification of two related pentapeptides from the brain with potent opiate agonist activity. Nature, 258, 577–579.
- Pert, C. B., & Snyder, S. H. (1973). Opiate receptor: demonstration in nervous tissue. Science, 179(4077), 1011–1014.
- Boecker, H., et al. (2008). The runner's high: opioidergic mechanisms in the human brain. Cerebral Cortex, 18(11), 2523–2531.