The primary chemical systems for pleasure are dopamine (anticipation and effort) and serotonin (immediate experience), with oxytocin associated with pair bonding and warmth, and testosterone with pursuit.

“And the currency of pleasure exists in multiple chemical systems, but the primary ones are the dopamine system, which is the anticipation of pleasure, and the work required to achieve the ability to experience that pleasure, and the serotonin system, which is more closely related to the immediate experience of that pleasure. And from dopamine and serotonin stem out other hormones and molecules, things like oxytocin, which are associated with pair bonding. Oxytocin is more closely associated with the serotonin system, biochemically and at the circuit level, meaning the areas of the brain and body that manufacture a lot of serotonin usually, not always, but usually contain neurons that also manufacture and make use of the molecule oxytocin. Those chemicals together create sensations of warmth, of, uh, wellbeing, of safety. The dopamine molecule is more closely associated with hormones like testosterone and other molecules involved with pursuit and further effort in order to get more of whatever could potentially cause more release of dopamine.”