Stem & Vein is made up of roughly 70% Stem & Vein and 30% leaf. This is due to the way S&V is made, which is not an exact science. During the making of stem & vein products, inevitably some of the leaf will accidentally get in there too. The alkaloids contained in stem & vein are different than the ones in the leaves. The unique set of alkaloids found in this Red S & V gives it qualities that are all its own.