I'm not a big believer in pre-workout supplements and the only things I would ever spend my $ on is creatine, caffeine tab, and maybe BCAA's. On that note the only thing I take is a caffeine pill before the gym. Majority/darn near everything sold at GNC is a waste of money. If I remember correctly the stuff isn't even regulated by the FDA, so who knows what's truly in it besides the people boxing it up in their garage.
I don't even bother with Whey protein anymore if that tells you anything. Haven't noticed any negative drawbacks either. Eating chicken, bison, turkey, and fish fills those needs. I gained 30lbs in one year eating nothing but quality food and it was pretty clean mass. So much for taking whey protein after the gym because of the fast digestive properties all of the supplement companies brainwash us with.
Ive been weight training for 13 years so I've learned a few things along the way. Nothing can replace good high quality food in large amounts when your stomach can tolerate it, especially some over the counter supplement.
When I'm flaring the only time I truly get relief is in the gym when I'm blasting myself with weights.
I'm not trying to be arrogant or come off as a ****** either just sharing the things I've learned along the way.