Letters from The Peptide Column.
Editorial commentary on regulation, research, and access. Each letter is sourced to primary literature and reviewed before publication.
Educational content only. Not medical advice. Substances discussed may not be FDA-approved for the uses described.
Peptide 101: Semaglutide — what it is, and what it actually does
The most talked-about molecule in medicine, explained from the ground up — plus the FDA's formal 503B notice, and one new review translated.
Everyone has heard of Ozempic. Far fewer can say what semaglutide is, how it works, or what the evidence does and doesn't show. This is the explainer — followed by this week's regulatory news and a new study, in plain English.
What the February announcement actually changed
An HHS Secretary signaled a peptide reclassification. The Federal Register did not.
In February, HHS Secretary RFK Jr. publicly suggested several peptides could move off the FDA's restricted compounding list. We've now had three months to watch the Federal Register. Here is what has — and has not — actually changed.
FDA's 503B GLP-1 exclusion proposal, in plain English
The agency proposed excluding semaglutide, tirzepatide, and liraglutide from the 503B bulks list. Comments close June 29.
On April 30, the FDA proposed adding three GLP-1 receptor agonists to the 503B 'Do Not Compound' list. We unpack what 503B is, what the proposal does, who it affects, and how the comment period works.
Six generic semaglutides in 24 hours
Novo Nordisk's Indian patent on semaglutide expired March 20. Six Indian generics filed launches the same day. The implications for U.S. patients are not what most coverage said.
India's patent system, U.S. patent protection, and the global gray market are three different stories. We separate them — and explain what the Indian patent cliff actually means for an American patient looking at semaglutide costs in 2026.
One careful letter every Sunday.
Free. Bias-checked. Under 1,200 words. Written for clinicians, patients, and the genuinely curious.
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