Medications
Compounded Semaglutide vs Ozempic: Why There Is B12 in the Vial
Patients bring me vials they bought online and ask whether the contents are the same drug that is in Ozempic. The answer usually depends on what is printed under the word semaglutide on the label, and most people have never been told to look there.
This is the part of the compounded GLP-1 story that almost nothing written for patients covers, so it is worth going through carefully.
The rule that made it legal, and the date it stopped
Semaglutide went into shortage in 2022. Federal law allows compounding pharmacies to prepare copies of a commercially available drug while that drug is on the FDA shortage list, which is the mechanism that produced the entire compounded semaglutide industry.
The FDA declared the semaglutide shortage resolved on February 21, 2025. With that declaration came two deadlines. State licensed compounding pharmacies, the ones the law calls 503A facilities, had until April 22, 2025 to stop. Outsourcing facilities, the larger 503B operations that produce in bulk, had until May 22, 2025.
Compounders challenged the deadlines in court. A federal court declined to issue a preliminary injunction, and the FDA confirmed the dates held in an update on April 28, 2025.
You will find articles that give February 2025 as the resolution date and articles that give March. The FDA’s own date is February 21, 2025. You will find very few that mention 503A or 503B at all, and almost none that give you the enforcement deadlines, which is the information you would actually need to evaluate whether a seller is operating lawfully.
Why there is B12 in your vial
Compounded semaglutide is frequently sold as a combination with cyanocobalamin, which is vitamin B12. Sellers commonly explain this as a measure to reduce nausea.
There is no evidence supporting that explanation. No approved labeling, no controlled trial, and no FDA statement describes cyanocobalamin as an antiemetic or as a tolerability agent alongside semaglutide. B12 is a legitimate vitamin, and GLP-1 medications can affect B12 status over time, but the nausea claim is marketing rather than pharmacology.
The actual reason relates to a specific phrase in federal law. A compounder is not permitted to produce something that is “essentially a copy” of a commercially available drug. One way to argue you are not making a copy is to make something different, and adding a second active ingredient is the most obvious way to do that.
The FDA addressed this directly and rejected it. From the agency’s compounding policy page: “FDA may consider a compounded drug product that combines semaglutide API and another API, such as vitamin B12 (cyanocobalamin), to be essentially a copy of a commercially available drug product when the drug products are used by the same route of administration,” subject to the conditions the agency sets out alongside that sentence.
Under the FDA’s 2018 guidance on this section of the law, a change to a compounded formulation only escapes the “essentially a copy” designation when the prescribing clinician has determined that the change produces a significant difference for that specific patient, and has documented that determination on the prescription. A vitamin added to every vial the pharmacy ships is a blanket formulation choice rather than a patient specific one, and does not meet that standard.
So when someone tells you the B12 is there to help with nausea, the more accurate description is that the B12 is there to make the product something other than a copy, and the FDA has said it does not accomplish that.
Semaglutide sodium and semaglutide acetate
The second thing to read on the label is whether the word semaglutide stands alone or has a salt name attached to it.
Ozempic, Wegovy, and Rybelsus all contain semaglutide base. Some compounded products have been made with salt forms, most commonly semaglutide sodium or semaglutide acetate. The FDA’s position on these is unusually blunt: “These salt forms, including semaglutide sodium and semaglutide acetate, are different active ingredients than are used in the approved drugs.” The agency has stated it is not aware of any lawful basis for their use in compounding.
That is not a fine distinction about purity. A different active ingredient means the safety and efficacy data from the semaglutide trials does not transfer to what is in the vial.
Know what is actually in your vial
If the label lists semaglutide sodium or semaglutide acetate, you are not taking the drug that was studied. The FDA has said as much about those salt forms.
The price that is not the price
The advertised monthly number and the amount that leaves your account are frequently different, and the difference lives in three places.
The first is the term. An introductory rate that applies to the first month or the first two fills, followed by a standing rate, is common. Read which one the headline number is.
The second is the commitment. Some programs require a multi month prepayment to access the advertised rate, and the refund terms on the unused months are usually where the actual cost sits.
The third is the dose. Compounded vials are frequently priced per vial rather than per milligram. As your dose escalates you draw more from each vial, so the monthly cost rises while the advertised price stays the same. A patient at a maintenance dose is not paying what a patient at a starting dose pays, even on the same plan.
Before the first charge, get three things in writing: what the price is after the introductory period ends, what happens to your money if you stop in month two, and what the cost becomes at the highest dose you might reach.
The reference point everything else is priced against is moving. In February 2026 Novo Nordisk announced that the list price of Ozempic, Wegovy and Rybelsus will fall by roughly a third effective January 1, 2027. Both branded manufacturers now operate direct self pay channels, and pharmacy discount programs change their pricing constantly.
The practical consequence is that the gap the compounded market was built to fill is narrowing, and any cost comparison you read that is more than a few months old is describing a market that no longer exists. Get current numbers from the manufacturer’s own self pay channel and from a pharmacy discount program before you commit to anything.
What the adverse event reporting shows
As of May 31, 2026, the FDA had received 990 adverse event reports associated with compounded semaglutide. Most of the articles ranking for this topic quote a figure from an earlier count, or quote none at all.
The reports cluster around a small number of problems. Dosing errors are prominent, and they follow from the delivery format: an approved pen is a metered device, and a vial with a syringe is a calculation done by the patient. Poison control data has flagged the risk of administering a multiple of the intended dose from vial based products.
There are also manufacturing concerns. Testing commissioned by Novo Nordisk reported unknown impurities in some compounded products at levels up to 33 percent.
The FDA’s current stated position, updated June 15, 2026, is that compounded GLP-1 products should be used only where a patient’s medical need cannot be met by an FDA approved product.
If you are already on a compounded version
Stopping abruptly is rarely the right move. A transition onto an approved product usually starts at the dose you are already tolerating.
What I tell patients who are already using it
A large number of people came to compounded semaglutide because the approved product was unaffordable or unavailable, and telling them they made a bad decision is neither useful nor fair.
What I ask is what the label says, whether the word semaglutide appears with a salt name after it, what the concentration is, and how they are measuring their dose. Those four answers tell me most of what I need to know. If the product is a salt form, that is the point at which I would want to move someone to an approved product or a different approach entirely.
The other thing worth saying plainly is that the reason to move off a compounded product is not that the compounded version is a scam. Many compounders are careful operators. The reason is that the legal basis for making it ended in 2025, which means the supply chain behind any vial still being sold is harder to verify than it was, and you have no way to audit it from your kitchen counter.
Common questions
Is compounded semaglutide the same as Ozempic? If it contains semaglutide base at the correct concentration, it is the same molecule. Whether it is the same product depends on the manufacturing, the purity, and whether it is a salt form. Those are the variables you cannot see.
Is compounded semaglutide still legal in 2026? The shortage based exemption ended with the FDA’s deadlines in April and May of 2025. Compounding remains lawful in narrow circumstances where an individual patient’s documented medical need cannot be met by an approved product. It is no longer lawful as a general lower cost substitute.
Why is compounded semaglutide cheaper? It is not manufactured under a New Drug Application, so it carries none of the development, trial, or regulatory cost of the approved product, and it is not sold through the same distribution and rebate system. The savings are real. The tradeoff is the absence of the oversight that the price difference represents.
Should I stop taking it? That is a conversation to have with a clinician who can look at your specific product and your specific situation, not something to decide from an article. Book a visit and bring the vial with you. Stopping abruptly has its own consequences.
What is the difference between 503A and 503B? A 503A pharmacy compounds for an individual patient against a specific prescription. A 503B outsourcing facility registers with the FDA and can produce in larger volumes without patient specific prescriptions, under more manufacturing oversight. Both were given deadlines to stop compounding semaglutide in 2025.
Bring the vial
What the label says, whether there is a salt name after the word semaglutide, the concentration, and how you are drawing your dose. Those four answers tell me most of what I need to know, and we can work out where to go from there.
Sources
U.S. Food and Drug Administration. FDA Clarifies Policies for Compounders as National GLP-1 Supply Begins to Stabilize.
U.S. Food and Drug Administration. FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. Updated June 15, 2026.
U.S. Food and Drug Administration. Compounded Drug Products That Are Essentially Copies of a Commercially Available Drug Product Under Section 503A of the Federal Food, Drug, and Cosmetic Act: Guidance for Industry. January 2018.
U.S. Food and Drug Administration. Declaratory order on the semaglutide injection products shortage.