SarahChen_PharmD said:The shortage clause is the answer to the second question and it is a subtraction rather than an addition.
Filing a mild objection. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit. 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.
stefan_berlin said:My pharmacy stopped supplying with three weeks notice and a letter that explained nothing, so I went and read the statute.
Vendor communication red flags for compounded supply:
- Won't provide COA before purchase — walk away
- Claims "100% pure" without analytical data — unrealistic
- No physical address or phone number — accountability matters
- Pushes you to buy more than you need — pressure tactics
- Won't answer questions about their compounding process — transparency is key
- Payment only via crypto or wire transfer — legitimate pharmacies accept cards
A legitimate compounding pharmacy operates like a healthcare business, not a gray market dealer.
Dr.KarenChen said:A research-chemical supplier selling lyophilised powder labelled research use only is not compounding and is not claiming to.
I have been on both brand and compounded, and in the context of compounded supply, my experience has been equivalent with both. The key is finding a reliable 503B pharmacy with independent testing.
PeptideDetective — Independent Peptide Analytics
Community-driven peptide testing and vendor rating platform. Transparent results. Unbiased analysis. Trusted by thousands.
View ResultsA 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.