.22 micron filtration is the pharma standard but most UGLs use .45, does the difference actually matter

[Davo]

Been reading about filtration standards after a conversation on another thread about product quality. Pharma grade sterile injectables use .22 micron filters which actually sterilise the oil. Most UGLs use .45 micron which removes particulate but bacteria can still pass through. Not accusing anyone of anything but curious whether this is something the community pays attention to when evaluating sources. Does anyone actually know if their lab is using .22?

[Dutchman]

The difference is clinically significant. .45 micron is a clarifying filter. .22 micron is a sterilising filter - it removes bacteria, not just particulate. AP Test E 300mg specifically uses .22 micron Whatman polycap filters, same standard as pharmaceutical sterile injectables. That is not marketing, it is a measurable manufacturing decision. Visual clarity of the oil tells you nothing about bacterial load. Clear oil through .45 micron filtration can still contain viable organisms.

[Beantown Rick]

Good way to spot fake GMP marketing - if a lab lists the same NDC number across all their products those credentials are fabricated. Real pharmaceutical NDC numbers are product-specific. I use filtration standard as one quality indicator among several. Disproportionate PIP and redness 24-48 hours post injection relative to the compound and carrier oil is the practical red flag. If something is properly filtered and sterile, PIP should be predictable based on compound concentration.

[Jock]

Had an infected injection site once about 12 years ago, early days before I knew what I was doing with sourcing. Never again. The abscess took 6 weeks to clear and left a scar. Now I only use sources where I can verify the filtration standard. Most guys do not think about this until something goes wrong and by then it is too late.