Buprenorphine is a long-acting weak opioid receptor activator that also blocks the receptor against strong activation. It suppresses withdrawal, restores a feeling of normalcy, and protects against overdose by blocking full activation of the receptors.
However, to understand how buprenorphine works, it’s helpful to understand the effects of other opioids like oxycodone or even heroin on the human body.
Opioids bind to and strongly activate a protein in the body called the “mu-opioid receptor.” Strong activation of this receptor causes euphoria, while very strong activation can lead to overdose and death.
Weak periodic activation is a normal part of the response to stress, pain, and other normal processes. Part of opioid withdrawal is caused by tolerance. This happens when a person who uses opioids becomes adapted to strong opioid receptor activation, and weak activation becomes inadequate to feel normal. Instead, in the absence of opioids, they feel pain, depression, and fatigue.