Quick question about tribulus

[Papi93]

I'm interested in getting some tribulus and i've read that a 15-20% protodioscin content is preferred. However when reading up on some brands, some of them use the terms protodioscin and steroidal saponins interchangably. Is this valid or are they just trying to make their product sound good. The product in question was tribulus fuel by twinlab, they have a pretty cheap price online. Also optimum nutrition's tribulus product is looking pretty good. Thanx for the help.

Twinlab contains a 20% protodioscin content so it is good to go. Optimum doesn't give a protodioscin content on their bottle. It does contain 40% saponin content. This pales in comparison to the 80% in Vitrex.