I'm sure QSC is paying for rHMG, and their supplier wouldn't take a shortcut by using the dirt cheap highly purified urine derived HMG from India, so I presume there are other impurities creating a side effect closely associated with the latter.
Other than a little bit of "ick" factor, they're equally effective anyway. I'm not sure if Jano's test distinguishes between the two. It looks to only be quantitative.
In any case, the filter will almost certainly reduce the site reaction by an order of magnitude or more. I've noticed the first post filtration dose of a site reaction inducing peptide is the best, and by a week later the site reaction from that vial returns to a degree (but still much better). I'm guessing that's because enough time has passed for more aggregation to take place. If I filter a single dose after this starts its back to being near reaction free, but per dose filtration can get expensive so you'll have to strike a balance.
I buy Pall from surplus science lab sources to get the supposedly better "Supor" PES material and they're still expensive, but this looks like a good source at a reasonable price (forget 4mm, the savings are next to nothing and they clog up fast when dealing with a "dirty" peptide). Holdup volume is only 2 units (.02ml) after you push 1ml of air through the filter to recover all the fluid you can:
DON'T get the type with the prefilter.
Hydrophilic PES syringe filters with single or double-layer membrane. Pore sizes of 0.2μm. Diameter of 13mm/25mm/33mm with Luer lock. Sterile individually packed.
shop.cobetter.com
