Mannitol is the filler. People used to say mannitol was added as a diuretic but the amount of mannitol in hGH vials is miniscule compared to what is used for diuresis. By orders of magnitude.
Wholly agreed, I was wondering if there are other fillers as well. For example, Genotropin contains mannitol, as well as sodium phosphate and glycine. I imagine sodium phosphate and glycine are used to control pH and improve solubility.
Probably a red herring in any case. I can't imagine the tiny amount of filler in something like Genotropin which contains mannitol and sodium phosphate having significantly different pharmacokinetics than Serostim which contains sucrose and phosphoric acid, again in tiny amounts.
I kinda want to settle the debate of one being somehow superior to the order to justify the order of magnitude difference in cost. My friend with whom I was having this discussion claims that serum IGF1 is pointless and the difference lies in intramuscular IGF1.
I'm not well-versed enough in the topic to debate the point, but from my perspective a good test, if this is true, would be to measure intramuscular IGF1 levels. 'Course this would take muscle biopsy and a $500 ELISA kit, a centrifuge, a microplate reader, and a bit of other lab gear.
Guess I'm wondering if that's worth pursuing or am I way off base?