There are many different products with apparently similar formulations on the market. How can I chose the right one ? Vitamin stability At the moment of the supply of the product the vitamin contents could be much lower than declared (due to cheap quality, bad mixing procedures, inadequate stocking etc). You have to be sure of the seriousness of your provider - the best guarantee is the control of the content of the unstable vitamins. Price The daily costs of the appropriate dose is of course an essential argument. Anti-doping control The existence of an official certificate of anti-doping control established by an independent laboratory is a guarantee.