If he's telling you that he is taking Viagra or some other health-related medication no, don't worry.  If he wants you to pop Oxycontin with him then yes, be suspicious.

It wouldn't matter if he is LE or not. I wouldn't see him. I wouldn't reply to his e-mail either. Just delete, block his e-mail, and move on. LE or not, this guy is trouble you don't need.

Shit could easily be laced or mixed and you could find yourself in a situation far worse than LE.
Please be safe out there, this world can turn real scary real quick.

then why the F*** would you be interested.  He wants to be your pusher, not your client.  And if he's pushing (I don't give a rat's *ss stolen Prescription drugs are still illegal) he could bring more heat with him, could be carrying drugs...  
Providing is about being discrete...  not hangin' with somebody likely to draw extra LE attention.
DELETE & BLOCK him.
skb

Sounds "coppy", even if it's not, druggies are tough appointments, slow and take fucking forever to get off. What if he dies and you're the last one seen going in? I'd avoid him.