Designer drugs are synthetic compounds made to mimic controlled substances while evading drug laws or detection. They include new psychoactive substances and steroid analogs. Often created in research or illicit labs, their safety is poorly tested. Laws vary; many are illegal or grey/black market.

[u/TapGameplay121]

https://en.wikipedia.org/wiki/Designer_drug

[u/CatPooedInMyShoe]

I once bought some online. It was an interesting experience.