Bronkaid is the brand name like the other guys said. Or if you want generic, just ask for generic asthma pills with ephedrine. You'll have to show your ID (reason is that meth cooks would purchase large quantities of ephedrine or pseudoephedrine to make drugs).
It will contain guafenisin, an expectorant, but oh well. It works.
I don't know if it's just me, but the behind the counter stuff just does't seem as potent as old school stuff. It could be because I wasn't consuming with caffeine at the time. Ripped Fuel used to cripple my appetite.