In a peer-reviewed cohort that measured it, yes: 94 people on compounded semaglutide with B12 lost a mean 4.11 kg, or 4.57% of body weight, over 3 months[1]. That sits near the 5.9% a Mayo Clinic cohort lost over the same 3 months on semaglutide at the trial doses[2]. No randomized trial has tested a compounded preparation, though, and the 14.9% figure from the STEP 1 trial was measured on the manufacturer’s product[3].
So the honest answer has two parts: the molecule works, and the trial evidence for that is strong. Whether a given compounded vial delivers the same molecule at the stated dose is a separate question, and the evidence on it is observational. Compounded preparations are not FDA-approved, which is covered in detail in whether compounded semaglutide is safe. This page stays on the narrower question of whether it produces weight loss.
What the compounded cohort measured
The study followed people in a weight management program at a commercial wellness studio between June 2023 and January 2024[1]. Each received a once-weekly injection of compounded semaglutide combined with cyanocobalamin, a form of vitamin B12. The dose started at 0.25 mg of semaglutide and could be titrated up to a maximum of 2.4 mg[1].
Of the 94 people analyzed, 81 were women and 13 were men, with a mean age of 46.57 years. After 3 months they had lost a mean of 4.11 kg, of which 2.67 kg was fat mass, while lean mass fell by 1.43 kg and skeletal muscle by 0.88 kg[1]. The authors concluded that meaningful weight loss is achievable on the combination outside a closely controlled environment.
Three limits sit inside that result, and the first is that there was no comparison group, so nothing separates the drug from the program around it. The follow-up was also 3 months, which is early in a titration schedule that climbs in steps toward 2.4 mg. And every author lists an affiliation with Restore Hyper Wellness, while the program itself ran at a commercial wellness studio[1]. The reason the B12 was in the vial at all is a regulatory one rather than a clinical one.
How that compares with the approved product
The closest comparison is a retrospective cohort at a Mayo Clinic weight management referral center. Its patients were prescribed weekly semaglutide at 1.7 or 2.4 mg, the doses used in the obesity trials[2]. Among the 175 analyzed at 3 months, mean weight loss was 6.7 kg, or 5.9%; among the 102 followed to 6 months, it was 12.3 kg, or 10.9%[2].
On its face, 4.57% against 5.9% looks close, but the two figures are not dose-matched. The Mayo patients were on 1.7 or 2.4 mg, while the compounded cohort began at 0.25 mg, and its abstract does not report what dose people had reached by month 3[1]. A figure taken partway through titration says little about the preparation either way.
The trial evidence sits further out: STEP 1 randomized 1,961 adults without diabetes to semaglutide 2.4 mg or placebo, alongside a lifestyle program, for 68 weeks[3]. Mean weight change was −14.9% against −2.4% with placebo, or −15.3 kg against −2.6 kg. Of those on semaglutide, 86.4% lost at least 5% of body weight, in a trial funded by Novo Nordisk that tested its own product[3]. How those figures translate to a reader’s own starting weight is worked through in how much weight people lose on a GLP-1.
Whether buying through telehealth changes the result
Many sellers on this site prescribe remotely, so the channel is worth separating from the product. A retrospective cohort drew a random sample of 4,500 people who started semaglutide for weight loss through a telehealth service between December 2022 and June 2023[4]. Of those, 655 reported a weight within two weeks of week 68, and their mean weight reduction was 16.6% (95% CI 16.0% to 17.1%)[4].
That is in line with the trial, and it suggests remote prescribing does not by itself cost results. Two things limit the reading, the first being that the abstract does not say whether the semaglutide dispensed was branded or compounded. The second is that the 655 who reported a week-68 weight are the people still engaged at that point, which favors those doing well[4]. Several authors list an affiliation with Roman Health Ventures, and the larger picture for remote care is set out in whether online GLP-1 clinics work.
What a weight-loss cohort cannot see
A cohort measures what happened to people but cannot tell you whether the next vial holds what the label says, which is where compounded products differ from approved ones. With the shortage over, compounders may legally sell only products that differ from the approved versions, in route, dose or added ingredients[5].
A survey of compounding sites in early 2025 found 33 such products. Of the 17 containing semaglutide or tirzepatide alone, 82% were sublingual and 18% were orally disintegrating tablets[5]. The reviewers wrote that whether these formats offer advantages over the approved oral tablet has not been determined. The cohort above used weekly injections, so its result does not carry over to a sublingual drop[1].
Potency has been tested on copies made outside the originator’s process. Analysis of 16 injectable and 8 oral follow-on semaglutide products found new impurities in the injectables, and several oral products held markedly less semaglutide than the label claimed[6]. Every author lists a Novo Nordisk affiliation, and Novo Nordisk makes the originator, a conflict covered in the impurity testing of compounded copies. The authors themselves say the effect on efficacy is unknown[6].
The starkest numbers come from outside the pharmacy system altogether: researchers placed test orders with illegal online pharmacies that sold semaglutide without a prescription, and 3 vials were delivered[7]. The samples held 28.56% to 38.69% more semaglutide than labeled, yet purity measured 7.7% to 14.37% against the 99% claimed[7]. That is a different route from a licensed compounding pharmacy, and what arrived from those orders is worth reading on its own terms. A dose that runs above its label is also the problem described in whether you can overdose on compounded semaglutide.
What “works” can mean on current evidence
Put together, the record supports a limited statement. Injected compounded semaglutide from a pharmacy program produced weight loss in one 94-person cohort, at a size broadly consistent with early results on the approved drug[1][2]. What it does not yet have is a randomized comparison, a follow-up longer than 3 months, or any outcome data for the sublingual and tablet formats now on sale[5].
The prescriber decides whether a compounded preparation is appropriate, and the dispensing pharmacy decides what goes into it. A reader can still ask for three things before paying: the pharmacy’s name, the dose in milligrams, and the route. How the post-shortage market changed which of those a seller publishes is covered in where compounded supply comes from now.