What is dynorphin?

Dynorphin is a type of neuropeptide involved in modulating pain and stress responses. When released, it binds to the kappa-opioid receptor (KOR), leading to feelings of agitation, stress, and discomfort. This process is particularly relevant in situations like deliberate heat exposure, such as using a sauna. The discomfort experienced in such scenarios is partly due to the release of dynorphin, which also activates the sympathetic nervous system, contributing to that fight-or-flight response.

Interestingly, this release of dynorphin and its binding to KOR can have long-term benefits. Over time, this process increases the receptors for feel-good endorphins, which bind to other opioid receptors like the mu-opioid receptor. This increase in endorphin activity can lead to feelings of well-being and mild euphoria after the initial discomfort of the dynorphin response subsides 1.