Never had problem cumming on V or C but I am pretty certain they make me last longer than I used to - if they stopped this guy cumming that would not be good.
Plus they only make you rock hard when you are stimulated - with the right girl that means that I am still rock hard AFTER cumming so the WG was right in a way
Look out for the herbal Golden Root Complex - it has less side affects than V and C. I get them on Ebay