L-ppa Question

Can somebody enlighten me? In the mag, it is often stated that phenylpropanolamine is much more thermogenic than ephedrine. In fact it states exactly this in ‘Gang of five’, issue 28. However, Bill has occasionally, and more recently, said that it is worth adding ephedrine to MD6 mk1, because although L-ppa is a very good anorectic it can’t match ephedrine in terms of thermogenesis. Surely this is a measurable effect and it is not open to interpretation. I purchased a fair stock of the original MD6 before it was pulled and just want to determine the truth about it’s effectiveness. I know what the cynical answer might be, but as I say, I’m not taking shots here I just wan’t to maximise my results. Sponge, any insight?