OxyContin is a brand name for a pain medication in the opioid class (narcotic drugs) that contains the extended-release version of oxycodone. Serious side effects of oxycodone include euphoria, anxiolysis and respiratory depression. There is significant overdose potential.
(See https://en.wikipedia.org/wiki/Opioid_epidemic_in_the_United_States)

Oxytocin is a neurotransmitter involved in breast-feeding and childbirth. It is also associated with empathy, trust, sexual activity, and relationship-building. It is sometimes referred to as the “love hormone,” because levels of oxytocin increase during hugging and orgasm. There is no overdose potential.

This meme remakes the saccharine sentiment, “Less Drugs, More Hugs.” It reformulates it to a more cerebral and acerbic taste. Its increased specificity amplifies the message impact, especially when contrasted with the generality of the original.

Example photo of a man and woman, each wearing a “Less Drugs, More Hugs” T-shirt, such as can commonly be found around the internet.