I still remember Glutamine, everyone was taking it. A competitive bodybuilder at work used to rave about it, she swore it helped her maintain the musclemass. Then it turns out in the end it's all absorbed and used by the intestines.
As for testosterone boosters - even if they do increase testosterone, there is no point to that since it doesn't make a difference according to our friend Layne Norton:
I reckon getting to bed on time and sleeping 8 hours will boost things way more than any pill anyway.