most cycles that run tests need winny at the end for its non-aritomzing effects.
your question is somewhat vague though. if you are asking if on a winny cycle, does winny have better effects at the beginning or end, then definately at the beginning. it is water-based and does not float around your system for three to four weeks like a lot of tests. i find that when i run long winny cycles that my strength gains top out after 5,6 weeks.