Stimulants Differentiating between meth, a-pvp, mdvp, and other synthetics?

[NeverGreen]

So I got some gear from a guy I met at a party who had given me good grade before. The effects lately seem to induce immediate chest/back pressure and I'm not sure if I respond oddly to amphs or what. What are some ways you guys would use with

Anyways how can I tell the difference between these chemicals in the absence of a test kit? What I received by all accounts looks like it should, tastes pretty bitter, etc, but I worry I'm injecting Flakka or something and these chest pains have me freaked out.

 

[kleinerkiffer]

There's no way to tell except with a proper lab test, because of that substance ID is against the rules

Chest pain could be due to anxiety or something more serious, so if you're not sure if it's real meth throw it away and get checked out