Semaglutide Sodium vs. Base: Why FDA Says Salt Forms Aren't the Same

FDA's position is that semaglutide sodium and semaglutide acetate are "different active ingredients" from the semaglutide base in Ozempic and Wegovy, and that it is "not aware of any lawful basis for their use in compounding." State pharmacy boards have turned that into explicit bans, and at least one now applies the same rule to tirzepatide salts. For patients, the practical question is simple: what form of the molecule did your pharmacy actually compound with?

What a "salt form" is

Many drug molecules can exist either as a free base or paired with a counterion, such as sodium or acetate, to form a salt. Salts can behave differently in solution and in manufacturing, which is one reason a drug's approved form is specified precisely in its application.

The approved semaglutide products use the base. The North Carolina Board of Pharmacy put it plainly in 2023: Ozempic and Wegovy contain semaglutide base, and "No salt form of semaglutide is contained in an FDA-approved drug" (NCBOP). The Kansas and Washington statements use nearly identical language (Kansas, 2024; Washington, 2024).

FDA's scientific concern is that it does not know whether the salts share the same chemical and pharmacologic properties as the base. Its October 2026 page describes the salts as ingredients that "are different active ingredients than are used in the approved drugs" (FDA). State boards echo FDA in saying salt-form products "have not been shown to be safe and effective" (Washington Medical Commission).

Why salts fail the federal compounding test

The legal argument is more decisive than the chemistry. Section 503A lets a pharmacy compound with a bulk drug substance only if it meets one of three conditions (21 U.S.C. 353a(b)(1)(A)):

1. It complies with an applicable USP or National Formulary monograph, if one exists;
2. If no monograph exists, it is a component of an FDA-approved drug; or
3. If neither, it appears on FDA's 503A bulks list.

Run semaglutide sodium through that test and it fails each step. North Carolina's board noted in 2023 that "There is no USP or NF monograph for semaglutide" (NCBOP). The approved drugs contain the base, not a salt. And Kansas's board notes semaglutide in any form is absent from FDA's bulks list (Kansas, 2024). That's why the boards conclude, in Washington's words, "no salt form of semaglutide may be used in a compounded drug product" (Washington Medical Commission).

The same statute also requires the bulk substance to come from an FDA-registered establishment with a valid certificate of analysis. A salt-form API can fail those requirements independently.

Does the same logic apply to tirzepatide?

The reasoning carries over, and at least one board has said so explicitly. Kansas's April 2026 statement says only the base form of semaglutide and tirzepatide is a component of an FDA-approved drug, treats salt forms of either as different active ingredients, and concludes that "no salt form of semaglutide or tirzepatide may be used in a compounded drug product" (Kansas Board of Pharmacy). If you use compounded tirzepatide, the same questions below apply.

FDA's statements, in order

Source: FDA and MDedge, as linked in each row.

The salt issue first surfaced while semaglutide was on FDA's shortage list. That backdrop is gone: FDA determined the semaglutide shortage was resolved on February 21, 2025, and the tirzepatide shortage on October 2, 2024, a decision it reaffirmed after reevaluation on December 19, 2024 (FDA). Salts were never acceptable during the shortage, and nothing about its end made them more so.

What state boards have done

Boards of pharmacy license the pharmacies that compound and dispense, so their statements carry direct disciplinary weight. Several have addressed salts by name:

Sources: NCBOP; Alabama BME; Kansas Board of Pharmacy (2026); Washington Medical Commission.

The Alabama statement is worth noting because it was aimed at physicians, not pharmacies. It warned that medical offices "may be purchasing semaglutide salts that do not meet federal requirements" (Alabama BME). The warning signals that salt products could reach patients through medical offices, not only through pharmacies.

Kansas's 2026 update is the broadest of the four. It covers tirzepatide as well as semaglutide, requires pharmaceutical-grade API from an FDA-registered manufacturer with a certificate of analysis identifying the original manufacturer, and says a pharmacist may not dispense a non-compliant compounded GLP-1 "even if lawfully purchased" (Kansas Board of Pharmacy). This list is not exhaustive; check your own state board for its current position.

What to check on your label and paperwork

Here's the frustrating part: a compounded vial label may read simply "semaglutide" or "semaglutide/cyanocobalamin" whether the API was the base or a salt. The label is a starting point, not proof. These checks get you closer:

1. Read the active ingredient line. If the label or pharmacy insert says "semaglutide sodium," "semaglutide acetate," or any other salt, that product uses an ingredient FDA says has no lawful compounding basis.
2. Ask the pharmacy directly, in writing. "Is the semaglutide (or tirzepatide) API in my prescription the base form?" A compliant pharmacy should answer without hesitation.
3. Ask what the API's certificate of analysis says. The product name on the manufacturer's COA is where the form is recorded. Our guide to reading a certificate of analysis explains the rest of that document.
4. Watch for "research use only." Peptides labeled for research use, or made by unregistered facilities, may not be used for compounding under any circumstances (NCBOP).
5. Don't treat added vitamins as a workaround. Kansas cites FDA's position that a product combining semaglutide with another ingredient such as vitamin B12 (cyanocobalamin) may still be considered essentially a copy of the approved drug when the route is the same and the amounts are within 10% of commercially available strengths (Kansas Board of Pharmacy). It also does nothing to change the form of the GLP-1 ingredient.

Where salts sit in the supply chain

Salt forms are mostly a sourcing problem. A pharmacy buys API from a supplier, and the supplier's paperwork determines what the pharmacy receives. FDA's GLP-1 import alert, which blocks GLP-1 APIs from foreign manufacturers that aren't on its "green list," was announced with salt forms named among the problems it was meant to address (FDA). Our article on the GLP-1 API supply chain explains how that list works.

For patients, the throughline is the same one that runs through every quality question on compounded GLP-1s: the label tells you less than the paperwork behind it, and a pharmacy that can't or won't describe its ingredient source is telling you something.

Sources

1. FDA, FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss (updated October 1, 2026)
2. MDedge, FDA Warns People to Avoid Compounded Semaglutide Medicines (June 2023)
3. FDA, FDA Launches Green List to Protect Americans from Illegal Imported GLP-1 Drug Ingredients (September 5, 2025)
4. FDA, FDA Clarifies Policies for Compounders as National GLP-1 Supply Begins to Stabilize
5. 21 U.S.C. 353a, Pharmacy compounding (Cornell LII)
6. North Carolina Board of Pharmacy, Statement Concerning Semaglutide Compounding (April 2023)
7. Alabama Board of Medical Examiners, Semaglutide statement (September 2023)
8. Kansas Board of Pharmacy, Semaglutide statement (April 2024)
9. Kansas Board of Pharmacy, Statement on Compounded GLP-1 and GIP Receptor Agonists (updated April 22, 2026)
10. Washington Medical Commission, Statement on Compounding Semaglutide (August 2024)

Medical disclaimer: This article is general information, not medical advice, and does not replace a licensed clinician who knows your history. Approvals, labels, coverage and prices change; check the linked sources and talk with your prescriber or pharmacist before making decisions about any medication.