I'm pretty sure esic-clean is the only syntol type product that contains collogen. I'm sure there are more, but that is the only difference that I am aware of.
BTW, I'm pretty sure esic-clean (sp?) is less then half the price. I purchased a bottle a few months ago for $65 on e-bay for bicept enhancement.....but I'm still too nervous to use it. I don't want to have lopsided uneven bicepts.