  We present experimental and theoretical results addressing the Reynolds
number (Re) dependence of drag reduction by sufficiently large concentrations
of rod-like polymers in turbulent wall-bounded flows. It is shown that when Re
is small the drag is {\em enhanced}. On the other hand when Re increases the
drag is reduced and eventually the Maximal Drag Reduction (MDR) asymptote is
attained. The theory is shown to be in excellent agreement with experiments,
rationalizing and explaining all the universal and the non-universal aspects of
drag reduction by rod-like polymers.
