Accepted answer
Worth being precise here: potency variation between compounders is a manufacturing-control question rather than an integrity question, and it is the predictable consequence of preparing a potent peptide by hand at small scale.
A beyond-use date for a compounded multi-dose preparation is set under USP chapter provisions on the basis of microbiological risk category and, where available, supporting stability data. In practice most beyond-use dates in this space are default values from the risk-category table rather than the output of a stability study, and the two should not be read as equivalent claims.
Twelve-month cost model, illustrative structure
| Line | Brand, insured | Compounded, subscription | Research-grade, self-tested |
|---|
| Product | Copay × 12 | Monthly fee × 12 | Vials × unit price |
| Consultation | Covered or copay | Bundled | Not applicable |
| Monitoring labs | Often covered | Usually not | Self-funded |
| Independent testing | Not applicable | Optional | Essential; per lot |
| Shipping | Pharmacy | Included | Per order |
| Dominant cost | Copay structure | Subscription fee | Testing |
Stated carefully, the salt-form point: the statutory pathway for compounding a copy of an approved drug during a shortage applies to the same active moiety as the approved product. A preparation described as a salt form — "semaglutide sodium", "semaglutide acetate" — is describing a different chemical entity from the approved base, and the description is usually there to construct an argument that it is not a copy. Whatever the legal merits, it means what is in the vial is not what was studied.
The statutory basis for the 503A/503B distinction is sections 503A and 503B of the US Federal Food, Drug, and Cosmetic Act as amended by the Drug Quality and Security Act of 2013, and the FDA’s guidance documents on each are the authoritative description of what is permitted.
Model twelve months, not one. The fee structures are designed to be compared monthly.
6Adding for future readers: the certificate should carry the lot number, not just a batch code. – leonid_marchuk 7 months ago add a comment