The stuff you buy online is made in what we call UG. Underground labs. If you can get enough Pharm grade to run cycles any of us would prefer that but it just isn't reasonable to do so unless you have good insurance and a really cool doc. On that note most UG stuff is good but you always risk getting something that is bunk or underdosed.
Try to find a good supplier whose products you are happy with and stick with them. There are places that you can go to check out sources if play around in google you'll find source reviews and can get a good idea of product quality that way.
Pharm grade. Awesome
UG Anywhere from Awesome-Bunk. Depends on the source