Comparisons

Wegovy vs Compounded Semaglutide

Published Sep 12, 2026 · 7 minute read

The molecule can be the same. Everything around it is different: who made it, who checked it, what it is dissolved in, and how the dose gets from the container into you.

Medical Supervision Required:Peptide Tracker is for private logging, calculations, reminders, inventory records, and education. It is not medical advice, dosing instruction, prescribing guidance, diagnosis, or a substitute for a qualified healthcare professional.

Key Takeaways

  • Wegovy is one product with one label, one manufacturer, and a trial record. Compounded semaglutide is whatever a given pharmacy made, with none of those.
  • Mass compounding was legal only while semaglutide was on the FDA shortage list. FDA declared the shortage over on February 21, 2025.
  • The approved drug is semaglutide base. Some compounded products use semaglutide sodium or acetate, salts FDA says are not the approved ingredient.
  • The dosing errors FDA has warned about come from vial arithmetic: a prescription in milligrams, a syringe in units, and a concentration that varies by pharmacy.
  • A poison-centre case series documented ten-fold overdoses from exactly that arithmetic.
Wegovy Compounded semaglutide
FDA status Approved, labeled Not approved, not reviewed
Made by Novo Nordisk A compounding pharmacy, 503A or 503B
Active ingredient Semaglutide base Semaglutide base, or sometimes a sodium or acetate salt
Container Single-dose pen, fixed dose Multi-dose vial, pharmacy-chosen concentration
Dose expressed as Milligrams on the pen Units on an insulin syringe
Dose ladder On the label None; prescriber’s choice
Trial evidence STEP, SELECT, ESSENCE None for any specific product
Expiry Manufacturer date Beyond-use date set by the pharmacy

What approval buys

An approved product has been checked for identity, strength, purity, and manufacturing consistency, and its label is built on trials that FDA reviewed. Those trials are the evidence base that a compounded product inherits by association but has never generated.

What the approved product has that a compounded one does not: trial evidenceMean percent weight change vs placebo in the Wegovy trials. No compounded semaglutide product has a published randomised trial
  • Wegovy dose
  • Placebo
2.4 mg, no diabetesSTEP 1 · 68 weeks · n=1,961
Wegovy dose
14.9%
Placebo
2.4%
2.4 mg, type 2 diabetesSTEP 2 · 68 weeks · n=1,210
Wegovy dose
9.6%
Placebo
3.4%
7.2 mg, no diabetesSTEP UP · 72 weeks · n=1,407
Wegovy dose
18.7%
Placebo
3.9%

STEP 1, 68 weeks: 14.9% vs 2.4%. STEP 2 in type 2 diabetes, 68 weeks: 9.6% vs 3.4%. STEP UP 7.2 mg, 72 weeks: 18.7% vs 3.9%.

Source: Wilding 2021; Davies 2021; Wharton 2025

SELECT added cardiovascular evidence: 6.5% of participants had a heart attack, stroke, or cardiovascular death on 2.4 mg versus 8.0% on placebo, over a mean 40 months in 17,604 people. Those numbers belong to a specific product at a specific dose. A vial of compounded semaglutide at a pharmacy-chosen concentration is not that product, even when the molecule is the same.

The shortage rule and February 2025

Federal law bars compounding what is “essentially a copy” of an approved drug, with one exception: while the drug is on the FDA shortage list. Semaglutide injection went on the list in 2022, and compounded semaglutide grew under that exception.

Feb 21, 2025FDA declared the semaglutide injection shortage resolved.
60 / 90 dayswind-down before enforcement: to April 22 for 503A pharmacies, May 22 for 503B outsourcing facilities.
10×overdoses documented in a poison-centre case series of compounded semaglutide administration errors.

After the wind-down, the shortage exception no longer applies. Compounding for a documented individual clinical need, such as an allergy to an excipient, remains possible. Mass production of copies does not. Compounding law also varies by state, and enforcement changes; the FDA shortage database shows the current status.

Salt forms

Wegovy contains semaglutide base. FDA has stated that some compounded products contain semaglutide sodium or semaglutide acetate, salt forms that are not the active ingredient in any approved product, and that the agency has no evidence they are safe or effective. The label on a compounded vial may say “semaglutide” either way. The pharmacy’s certificate of analysis is the only place the form is stated.

Where dosing errors happen

A Wegovy pen delivers one fixed dose. There is no arithmetic.

A compounded vial carries a concentration, typically between 1 and 10 mg/mL and set by the pharmacy. The prescription says milligrams. The syringe says units. The same 0.25 mg dose reads differently on the syringe depending on which vial was dispensed:

Vial concentration 0.25 mg in units 0.25 mg in mL
1 mg/mL 25 units 0.25 mL
2.5 mg/mL 10 units 0.10 mL
5 mg/mL 5 units 0.05 mL
10 mg/mL 2.5 units 0.025 mL

The poison-centre series is what this table looks like in practice: two patients self-administered ten-fold overdoses, one dosed in millilitres and units instead of milligrams, and all three had nausea, vomiting, and abdominal pain lasting days. FDA’s alert on compounded semaglutide and tirzepatide describes the same failure, with some patients drawing five to twenty times the intended dose. A refill at a different concentration is the classic trigger.

The dose calculator does the arithmetic. It cannot supply the concentration; only the pharmacy label can.

Dose steps with no label

Wegovy’s ladder is on the label: 0.25 mg for four weeks, then 0.5, 1, 1.7, and 2.4 mg, each held at least four weeks. Compounded semaglutide has no label and therefore no official ladder. Prescribers often borrow the Wegovy or Ozempic steps, but nothing requires that, and some compounded prescriptions use in-between doses that exist on no label at all.

Storage

A pen has a manufacturer expiry. A compounded vial has a beyond-use date set by the pharmacy, usually shorter, counted from preparation rather than from first puncture. Multi-dose vials also accumulate stopper punctures. The beyond-use date calculator gives a discard date from the interval on the label.

Which comparison you wanted

If you log a compounded product, record the concentration on the vial with every dose. That single field is what makes a later export readable. How GLP-1 tracking works covers the rest.

8. Wegovy vs Compounded Semaglutide FAQ

  • Is compounded semaglutide the same as Wegovy?

    It may contain the same molecule, or a salt of it, but it is not the same product. Wegovy is FDA-reviewed for identity, strength, purity, and manufacturing, and carries a label built on trials. A compounded product has no FDA review, no label, and no trial. Its quality depends on the individual pharmacy.

  • Is compounded semaglutide still legal in 2025 and 2026?

    Pharmacies may compound a copy of an approved drug in bulk only while it is on the FDA shortage list. FDA removed semaglutide injection from the list on February 21, 2025, with wind-down periods ending in April for 503A pharmacies and May for 503B outsourcing facilities. Compounding for a documented individual need remains possible; mass-produced copies do not.

  • What is semaglutide sodium?

    A salt form of semaglutide. FDA has stated that semaglutide sodium and semaglutide acetate are not the active ingredient in the approved products and has no evidence they are safe or effective. Some compounded products used them because the base was hard to source.

  • Why do dosing errors happen with compounded semaglutide?

    The prescription is written in milligrams, the vial is labeled in mg/mL at a concentration the pharmacy chose, and the syringe is marked in insulin units. Three units in one workflow. A poison-centre series reported patients drawing ten times the intended dose. A Wegovy pen delivers a fixed dose with no arithmetic.

  • Does this page tell me which to use?

    No. It compares what the two are. Whether to use any semaglutide product is a prescriber decision, and compounding law varies by state.

9. Sources

References used for this article

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