well, it seems to me like it works your lower bicep. NO, it doesn't actually lengthen the bicep, it only works the lower bicep therfore developing the area. This development will possibly lead to the appearance of the bicep being longer by virtue of the fact that it is more developed where it does insert. I did not mean that it will lengthen, you got what you got as far as that goes, but you can develop what you do have.