The short answer: you switch by getting a new prescription for Wegovy, Zepbound, or one of the new pills, and your prescriber picks the starting dose. A compounded dose does not convert cleanly to a brand dose, so the number on your old vial is a clue rather than an instruction.
If you have been off for more than a couple of weeks, or nobody can tell you exactly what was in your vial, the safest default is to restart near the bottom of the label schedule and climb. That costs you some weeks. Guessing high can cost you days of vomiting.
Why your compounded supply is drying up
Pharmacies were allowed to copy semaglutide and tirzepatide while the brand products were in shortage. The shortages ended. FDA declared the tirzepatide shortage resolved on October 2, 2024, confirmed that on December 19, 2024, and declared the semaglutide shortage resolved on February 21, 2025. The enforcement grace periods for state-licensed pharmacies and outsourcing facilities then closed in steps through the spring of 2025 (1).
2026 has added pressure from the other direction. FDA’s April 1, 2026 update says plainly that tirzepatide and semaglutide are on neither the 503B bulks list nor the drug shortage list (1). On April 30 the agency proposed excluding semaglutide, tirzepatide, and liraglutide from that bulks list permanently, with a comment period that closed July 30 after an extension (2). And on March 3 it sent warning letters to 30 telehealth companies over marketing that implied their compounded products were the same as approved ones (3). As of early November 2026 there was no final decision on the bulks proposal, so treat that piece as pending.
A narrow lane survives. FDA will not treat a compounded product as essentially a copy when a prescriber determines and documents a change that makes a significant difference for an identified patient (1). It also says a semaglutide plus B12 product can still be judged a copy when both strengths fall within 10 percent of the commercial products (1). If your supplier is shipping less, relabeling, or closing its compounded program, this is the reason. It is a regulatory story and says nothing about you.
I covered the safety checklist and the history in Compounded Semaglutide and Tirzepatide: What to Know Now. This post is the practical follow-up for someone who has to make the move.
Why can’t I just convert my compounded dose?
Because the label on a compounded vial and the label on a pen are written in different languages, and sometimes describe different molecules.
Start with units. Compounded product usually arrives in a multi-dose vial that you draw up with a syringe. A poison control case series in the Journal of the American Pharmacists Association described three patients with adverse events after compounded semaglutide, two of them 10-fold dosing errors, and one who was dosing in milliliters and units instead of milligrams. One needed an antiemetic and intravenous fluids (4). A pen clicks to a fixed dose. A syringe asks you to do arithmetic.
Then the ingredient. FDA states that semaglutide sodium and semaglutide acetate are different active ingredients from the one in the approved drugs, and says it knows of no lawful basis for using those salts in compounding. It has also logged reports of patients getting more product per dose, dosing more often, or titrating faster than the label allows (5). As of May 31, 2026, the agency counted 990 adverse event reports tied to compounded semaglutide and more than 730 tied to compounded tirzepatide, and it says underreporting is likely (5).
So a compounded vial labeled “2.5 mg weekly” and a Zepbound 2.5 mg pen share a number. They do not share a guarantee.
Restart low, or match the dose?
No label tells you how to switch from a compounded product, because none of them contemplate it. What the labels do tell us is how to restart after a gap, and that is the closest evidence we have.
The Wegovy label says that if two or more consecutive weekly doses are missed, reinitiate dose escalation at a lower dosage to reduce the risk of gastrointestinal adverse reactions (6). The Zepbound label addresses only a single late dose (7), but Lilly’s medical information page describes what the SURMOUNT trials did: after one or two missed doses, treatment restarted at the same dose if it had been well tolerated, and after three or more, it restarted at 5 mg regardless of the prior dose (8). The Foundayo label sets its trigger at seven or more consecutive missed daily doses, again with reinitiation at a lower dosage (9).
Read together, gap length is the first variable. A short gap on a known, well-tolerated dose makes matching defensible. A longer gap pushes you down the schedule. The second variable is certainty. If the pharmacy is unknown, the concentration is unclear, or the patient cannot say how many units they drew, leaning low is the safer choice. My view is that the two errors are not symmetrical. Starting too low delays the result by a few weeks. Starting too high can mean days of vomiting and, rarely, a trip for fluids.
For scale, here is what low looks like. Wegovy starts at 0.25 mg and reaches 1 mg at week 9, with each step lasting four weeks. Zepbound starts at 2.5 mg and reaches 5 mg at week 5 (6,7). The Wegovy label also allows delaying escalation by four weeks if a dose is not tolerated (6).
There is no single number I use. If someone has been getting their medication through a reliable compounding pharmacy, that helps, because there is likely to have been no gap in dosing. If the pharmacy is unknown, or there is some question about how they have felt on the compounded drug, I adjust. Where I start depends on how the patient is doing, which pharmacy and which medication they were using, and whether they have been sick to their stomach or have seen no change in their hunger at all. If they were having side effects on the compounded product, such as nausea bad enough to need a lot of ondansetron, or severe diarrhea or constipation, but they want to try a brand-name medication to see whether that improves, I start them on a lower dose than they were taking. If they have been on a particular compounded dose for a long time and are not losing any weight, I might start higher than the label’s starting dose. It really depends.
What I would gather before the video visit
On a video visit I cannot pick up the vial, so the vial has to come to me as photographs. The useful list is short: the pharmacy label showing drug, concentration, and lot; the syringe type; how many units the patient draws; the date and size of the last injection; the highest dose reached; and every side effect along the way. Patients who bring that make the dose decision easy. Patients who bring “it was the blue one” make it a judgment call.
What I ask for is a photo of the current prescription. It has to show the name of the medication, the dose, the date it was prescribed, and the prescribing doctor. It also has to show any additives, because compounded versions sometimes include them, and I want to see exactly what has been in that vial.
What restarting will feel like
Expect the early weeks of a new start, even if you were on a high dose before. The labels build their escalation schedules specifically to reduce GI side effects (6,7), and tolerance you built on a product of uncertain strength is not a reliable credit. Nausea, early fullness, and constipation are the usual complaints. If a step is rough, hold there rather than push, which the Wegovy label explicitly permits (6).
Some patients feel like they are going backward when the dose drops. They are not. The goal is to land on a dose you can verify, then climb to the effect you want. Persistent vomiting, or an inability to keep fluids down, is a reason to call. My side effects post has the incidence numbers.
What will the brand version cost?
Less than many people expect, though prices move. As I write this, NovoCare lists the Wegovy pen at $199 a month for new patients on the first two fills of the 0.25 mg and 0.5 mg doses, then $349 a month for 0.25 through 2.4 mg, and the Wegovy pill from $149 a month, rising to $299 at the 9 mg and 25 mg strengths. Lilly lists Zepbound self-pay starting at $299 a month for the KwikPen or four vials, and the $449 price on higher doses, pen or vial, requires a refill within 45 days, otherwise it goes to $499 at 7.5 mg and $699 from 10 mg up (11). Novo’s offer runs through December 31, 2026 and it says pricing will be updated after that (10). Lilly’s page lists no end date.
Both routes need a prescription. Novo’s prices apply when it is filled through NovoCare Pharmacy or with its savings offer (10). If you have insurance, check coverage and prior authorization first, since a covered fill beats any cash price. My cash pay prices post tracks the full ladder, including Medicare and the other federal programs.
Pills as a way out
Needles and syringes are part of why some people used compounded vials in the first place, and now there are two oral choices. Wegovy tablets start at 1.5 mg daily for 30 days, then 4 mg, then 9 mg, then 25 mg (6). Foundayo starts at 0.8 mg, steps to 2.5 mg after at least 30 days, then 5.5 mg, with room to 9, 14.5, or 17.2 mg (9). The Wegovy label does include a rule for moving from the 2.4 mg injection to the 25 mg tablet. Nothing in either label covers moving from a compounded injection, so the same logic applies: start at the bottom unless there is a good reason not to (6,9). I compared the two pills in Foundayo vs. the Wegovy Pill.
For most people it comes down to two things, preference and coverage. If insurance will help pay for Foundayo or the Wegovy pill, that is probably the most important deciding factor. If the patient is paying cash, that changes the math. And if someone doesn’t like injections, a pill usually makes more sense, as long as it is affordable and it keeps them on the medication.
Gray-market sellers and “research use” vials
When a compounded supplier folds, the next search result is often worse. FDA has warned companies that sold semaglutide, tirzepatide, and related peptides falsely labeled “for research purposes” or “not for human consumption” while supplying dosing instructions to consumers. It also says it is aware of counterfeit Ozempic, and advises buying only from state-licensed pharmacies (5). A price far below the brand cash prices above is the tell. Use FDA’s BeSafeRx tools if you are unsure about a site.
The same caution covers telehealth ads. FDA’s position is that compounded drugs are not FDA-approved (3), so a site promising “the same as Wegovy” is making a claim the agency has already penalized.
If you are the patient
Do not stretch your last vial to bridge the gap, and do not mix products. Photograph the label now, write down your last dose date, and book the switching visit before you run out. Ask your prescriber which brand product fits your coverage and budget, and expect a lower starting dose than you were on.
If you are the clinician
Document the compounded product, the pharmacy, the last dose date, and your reasoning for the starting dose, since no label supports a direct conversion. Counsel on the GI risk of reinitiation (6,7). Remember that state-licensed pharmacies that are not outsourcing facilities are not required to report adverse events to FDA, so your MedWatch report may be the only one (5).
The Bottom Line
Moving from compounded semaglutide or tirzepatide to Wegovy, Zepbound, or an oral option means a new prescription and a starting dose chosen for you, because compounded doses do not convert cleanly to brand doses.
Gap length and certainty drive the choice. A short gap on a verified, well-tolerated dose can be matched. A longer gap or an uncertain vial points toward the label starting dose and a four-week-step climb. Costs for the brand products are lower than they were, and the pills give needle-averse patients a path. Avoid gray-market sellers entirely.
Related Reading
Compounded Semaglutide and Tirzepatide: What to Know Now
Wegovy and Zepbound Cash Pay Prices Without Insurance (2026 Update)
Foundayo vs. the Wegovy Pill: Comparing the Two New Weight Loss Pills
Weight Loss Drug Side Effects and How Common They Are
Wegovy 7.2 mg: Who Should Consider the Higher Dose?
More on Weight Loss & Metabolic Health
Scott Rennie, D.O.
Board Certified in Obesity Medicine and Family Medicine
This blog is for educational purposes only and does not constitute individual medical advice. Always consult your own physician before making changes to your health, medications, or treatment plan.
Sources
- U.S. Food and Drug Administration. FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize (current as of April 1, 2026). https://www.fda.gov/drugs/drug-alerts-and-statements/fda-clarifies-policies-compounders-national-glp-1-supply-begins-stabilize
- U.S. Food and Drug Administration. FDA proposes to exclude semaglutide, tirzepatide, and liraglutide on 503B bulks list. April 30, 2026. https://www.fda.gov/news-events/press-announcements/fda-proposes-exclude-semaglutide-tirzepatide-and-liraglutide-503b-bulks-list
- U.S. Food and Drug Administration. FDA warns 30 telehealth companies against illegal marketing of compounded GLP-1s. March 3, 2026. https://www.fda.gov/news-events/press-announcements/fda-warns-30-telehealth-companies-against-illegal-marketing-compounded-glp-1s
- Lambson JE, Flegal SC, Johnson AR. Administration errors of compounded semaglutide reported to a poison control center: case series. J Am Pharm Assoc (2003). 2023;63(5):1643-1645. PMID 37392810. https://pubmed.ncbi.nlm.nih.gov/37392810/
- U.S. Food and Drug Administration. FDA’s concerns with unapproved GLP-1 drugs used for weight loss (current as of October 1, 2026). https://www.fda.gov/drugs/drug-alerts-and-statements/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss
- Wegovy (semaglutide) injection and tablets, prescribing information (revised June 2026). DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ee06186f-2aa3-4990-a760-757579d8f77b
- Zepbound (tirzepatide) injection, prescribing information. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=487cd7e7-434c-4925-99fa-aa80b1cc776b
- Eli Lilly Medical Information. What should a patient do if they miss a dose of Zepbound (tirzepatide)? https://medical.lilly.com/us/products/answers/what-should-a-patient-do-if-they-miss-a-dose-of-zepbound-tirzepatide-209169
- Foundayo (orforglipron) tablets, prescribing information. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=8ac446c5-feba-474f-a103-23facb9b5c62
- Novo Nordisk. NovoCare: Wegovy savings and self-pay options. https://www.novocare.com/wegovy/savings-card.html
- Eli Lilly and Company. Zepbound savings and insurance options. https://zepbound.lilly.com/savings
