This article is educational and does not replace medical advice. Prescription medication requires review by a licensed clinician and, when appropriate, a valid prescription. Compounded medications are not FDA-approved.
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Written by Kim Callender, NP, FNP-BC·Reviewed by Jonathan Snipes, MD·Published August 7, 2026·Last reviewed August 7, 2026·Prices verified August 7, 2026·Methodology v1.0

Semaglutide base, acetate or sodium? The question almost nobody asks

FDA has repeatedly distinguished semaglutide base — the active ingredient in the approved products — from salt forms such as semaglutide sodium and semaglutide acetate, and has linked the salt forms to safety concerns. It is one of the few technical details in this market a patient can actually verify before paying.

What to ask, and what a good answer looks like
QuestionGood answerIncomplete answerThe answer that ends it
Which form does your pharmacy compound from?Semaglutide base, named explicitly‘Pharmaceutical-grade semaglutide’Cannot say / proprietary
Can I see a certificate of analysis for my lot?Yes, provided on requestAvailable on request from the pharmacyNo COA process
Which pharmacy fills the prescription?Named, with a state licence number‘A licensed 503A partner’Proprietary partnership
Is anything else in the vial?Stated: e.g. B12, with a reason‘Proprietary blend’Not disclosed
What is the beyond-use date?Printed on the vialRoughly 28 daysNot stated

Why the distinction matters

The approved products contain semaglutide base. A salt form is a chemically different substance with different properties, and it is not what the pivotal trials studied. FDA has been explicit that salt forms are not the same active ingredient as the approved drug.

This is not a theoretical distinction. It became a live issue when the compounded market expanded rapidly during the shortage and some supply chains sourced whatever active ingredient was available.

The B12 question

Many compounders add cyanocobalamin to semaglutide. Two things are true at once: it is a formulation choice, and it is also an argument that a combination product is not essentially a copy of an approved drug, which matters for what may lawfully be compounded.

Programmes that market B12 as a clinical enhancement are marketing a regulatory position as a feature. Ask what is in the vial and why, and judge the answer on whether it is specific.

What this tells you about a programme

A programme that answers precisely is one that supervises its supply chain closely enough to know. One that cannot answer has told you something about how far its oversight extends, whatever its price or its marketing says.

Frequently asked questions

Is semaglutide acetate the same as semaglutide?
No. FDA distinguishes the base peptide used in approved products from salt forms including acetate and sodium, and has linked the salt forms to safety concerns.
How do I find out which form my programme uses?
Ask in writing which form the compounding pharmacy uses, and request the certificate of analysis for your lot. Good operations produce one on request.
Does adding B12 make compounded semaglutide better?
There is no evidence it improves weight outcomes. It is a formulation decision that also supports an argument about what may lawfully be compounded.