First time ordering compounded - what do I even look for??

BenResearch_OR said:

They are two different exemptions from the same federal requirements and they buy different things.

This is where I part company with the consensus forming above. A research-chemical supplier selling lyophilised powder labelled research use only is not compounding and is not claiming to. It is a different legal universe with no pharmacy oversight, no patient relationship and no content guarantee, and conflating the two in these threads helps nobody.

Correct me if the detail matters more than I have assumed.

nick_newbie said:

My pharmacy stopped supplying with three weeks notice and a letter that explained nothing, so I went and read the statute.

Compounding pharmacy customer here with experience relevant to compounded supply.

I've ordered from 5 different compounding pharmacies over the past 18 months. The quality variation is real — purity ranged from 94% to 101% of label claim based on independent Janoshik testing.

My current compounder (a 503B facility) has been consistently 98-101% purity across 5 orders. I pay $112/month vs $1,302 for brand. The savings are substantial and the product is equivalent in my experience.

Re: compounded supply — this applies whether you're using brand or compounded. The clinical principles are the same.

Dr.PeteFamMed said:

A research-chemical supplier selling lyophilised powder labelled research use only is not compounding and is not claiming to.

GMP compliance checklist relevant to compounded supply compounding quality:

• Clean room environment with HEPA filtration
• Environmental monitoring (viable and non-viable)
• Personnel training and competency assessment
• Validated analytical methods for testing
• Stability testing program
• Complete batch records and traceability
• Quality management system with deviation handling

A 503B pharmacy following cGMP should be able to answer questions about ALL of these if you ask. Don't be afraid to ask — it's your health.

A narrower follow-up, since the general answer is now clear:

What actually distinguishes 503A from 503B, in terms of what each may make and from what starting material?

Closing the loop on my own question.

The bulks-list asymmetry was the piece I had missed entirely. It explains why one of my two pharmacies is still arguing it can supply and the other simply stopped.