Recommended by my cohorts in the medical community, I started with Apex. They were safe, fast, reliable and accepted credit cards. Apex also offers several coupons and a Hero discount to Military and Medical personnel. COA’s are available on their website and are more frequently updated than in their upstart days. Unfortunately, as Apex’s popularity has grown, their pricing has increased, in some instances $50 to $100 a vial in the course of a week. This pricing variability sent me searching for an alternate vendor, however, in a pinch, I would not hesitate to order from Apex again. I know the ease of ordering, how quickly they ship, the quality of the product, and the demonstrated results, I just wish their pricing was as reliable.