In people

The human record on this molecule is small, old and specific, and it is all spinal or into a vein, given by doctors. After surgery, 20 micrograms into the spinal fluid produced relief described as profound, lasting about 43 hours from one placement, and those patients went home earlier. Infused into a vein in healthy people the endocrine system answers clearly: prolactin, growth hormone and thyrotropin rise, cortisol falls, renin activity climbs, and naloxone abolishes all of it, which is the clean proof that it is working through opioid receptors. It carries everything else a strong mu agonist carries, and that is the honest centre of this entry: breathing slows, and at high amounts into the brain fluid animals showed catalepsy, a frozen immobility. Tolerance and dependence do develop with repeated exposure, less steeply than with morphine but really. In Russian work on ground squirrels it dropped body temperature and slowed the whole animal into a sleep-like state. Nothing in its history involves a person giving this to themselves, and its potency is exactly why.