Funny enough OxyContin actually causes a temporary increase in cortisol. Opioids cause a stress response, body reacts by stimulating the HPA axis, and cortisol is released. Though long term use lead to dysregulation in cortisol levels and eventually blunted or irregular cortisol levels. withdrawal leads to spikes, and both withdrawal and chronic use lead to difficulty managing stress as a result
The more you know
This isn’t wrong, per say, but it’s an oversimplification of a complicated relationship
Cortisol can influence how sensitive the body is to oxytocin, for one. Similarly chronic stress can inhibit oxytocin release. Most people can recognize this effect: high stress scenarios lower the effect of all the stress remedies you’ve suggested. Doesn’t mean to not try them of course
The timing and context of cortisol release play an important role in whether it supports or hinders oxytocin's effects. Short-term stress responses might be adaptive, while long-term chronic stress can be harmful to the body's oxytocin system. As a result cortisol isn’t inherently “bad”. (This is aside from its role in metabolism, insulin response, circadian rhythms, etc)