I always drink the clen down with coffee and I feel fine,actually I feel great on that mix.The caffiene somewhat takes away the slight headache I get from the clens.Oh yeah it's clen,not clem.
well I've been drinkin coffee since like 3rd grade so I have a tolerance,plus it makes me happy.And no it never stunt(sp) my growth,I'm 6-0 170 no problems from the coffee here.