Weight loss and metabolic peptides — GLP-1 and beyond

The single most useful frame for this category, in late 2026, is the regulatory one. The drugs people talk about as if they were interchangeable have very different legal lives.

FDA-approved and on US pharmacy shelves. Most of the compounds in this category have approved drug labels in Drugs@FDA ^[1]. Semaglutide is approved as Ozempic (subcutaneous, NDA 209637) for type 2 diabetes, as Wegovy for chronic weight management, and in tablet form as Rybelsus and, since its label was revised in January 2026, Ozempic tablets, both for type 2 diabetes. Wegovy tablets, approved in December 2025 and launched in January 2026, are the oral semaglutide for weight management ^[1]. Tirzepatide is approved as Mounjaro (NDA 215866) for type 2 diabetes, and since August 2026 also to reduce cardiovascular risk in adults with type 2 diabetes at high risk, and as Zepbound (NDA 217806) for chronic weight management ^[21].

Liraglutide, the first-generation drug in the class, is now off-patent. Besides the originator products, Victoza and Saxenda, FDA lists eleven approved generic versions, three of them rated as substitutes for Saxenda, the weight-management product ^[1]. Tesamorelin is the GHRH analog approved as EGRIFTA SV (BLA 022505, Theratechnologies) — but only for HIV-associated lipodystrophy, not general weight management.

Foundayo, Eli Lilly's orforglipron tablet, was approved by FDA on April 1, 2026 and launched in US pharmacies on April 9 ^[2]. It is the first oral small-molecule GLP-1 receptor agonist — distinct from oral semaglutide because it doesn't require the strict fasting and water-intake restrictions that the Wegovy pill carries.

Compounded, not approved. Compounded versions of semaglutide and tirzepatide drove most of the telehealth weight-loss market between 2022 and 2025. The doorway that allowed that was the FDA shortage exemption. Both drugs were on the FDA Drug Shortages list in 2023 and most of 2024. FDA confirmed the tirzepatide shortage resolved on December 19, 2024, and the semaglutide shortage on February 21, 2025 ^[20]. Once a drug is off the shortage list, the "essentially a copy" prohibition reasserts and large-volume compounding becomes much harder to justify under either Section 503A or Section 503B. The architecture is detailed in our compounded vs branded peptides explainer — short version, the supply pathway most telehealth providers used is now closed for these molecules. What remains is narrower: a 503A pharmacy compounding for a named patient whose prescriber documents a clinically significant difference from the approved drug, and the 503B bulk route that the rulemaking below would shut.

Research-only or narrow-use. AOD-9604 is a fragment of human growth hormone that has been studied for fat reduction; it is not approved as a drug for weight loss in the US and the human evidence base is thin. It is most often sold as a research compound or compounded from a 503A pharmacy on physician request. The category overlaps the growth-hormone-secretagogue cluster (CJC-1295, Ipamorelin, Sermorelin), which has its own canonical home under performance and longevity — see the cross-cutting rail at the foot of this page.

In 2026 the FDA moved against compounded GLP-1s on two fronts, supply and marketing, and patients on compounded products should understand both.

The supply side. On April 30, 2026, FDA proposed excluding semaglutide, tirzepatide, and liraglutide from the 503B bulks list — the list of bulk drug substances that outsourcing facilities are allowed to compound from ^[3]. The agency wrote that it "did not identify a clinical need for outsourcing facilities to compound semaglutide, tirzepatide, and liraglutide from bulk drug substances." Public comment was due by the end of June 2026 and was later extended to 30 July 2026. The agency now weighs the docket before a final determination; none had been published as of 4 November 2026. If finalized, the proposal closes the main remaining legal pathway for 503B outsourcing facilities to make these drugs from active pharmaceutical ingredient.

The marketing side. Two months later, on June 8, 2026, FDA's Office of Compounding Quality and Compliance issued a batch of warning letters to telehealth companies marketing compounded GLP-1s with false or misleading claims. Twenty-five letters in that batch went to telehealth companies, including two we review, Maximus and Eden. The four claim patterns FDA flagged in the batch — implying FDA approval, calling the source pharmacy "FDA-approved," equating the compound to the branded drug, and putting the telehealth brand's name on the vial — are the marketing copy that built the category. Letters of the same kind have kept coming since, most recently to RonanRx on October 30, 2026.

Both threads point the same direction. The window for cheap compounded GLP-1s, which was already narrowing, is narrowing further. The FDA-approved alternatives are scaling fast enough to take the demand.

The evidence base is now mature enough that the case-control comparisons matter more than the individual trial headlines. Three threads are worth knowing.

Semaglutide as the baseline. STEP 1 reported about 15% mean body-weight loss at 68 weeks with weekly subcutaneous semaglutide 2.4 mg versus about 2.5% with placebo, in adults with overweight or obesity without diabetes ^[4]. STEP 3, STEP 4, and STEP 8 followed with variations on lifestyle support, withdrawal maintenance, and a head-to-head against liraglutide ^[5]. The pattern is consistent. The withdrawal data — the STEP 1 trial extension — showed that participants regained about two-thirds of lost body weight within a year of stopping the drug ^[6]. That is the trial readout that should anchor any expectation a patient has about long-term outcomes: GLP-1 weight loss is a maintenance therapy, not a course.

Tirzepatide as the higher-ceiling alternative. SURMOUNT-1 reported about 20% mean body-weight loss at 72 weeks at the highest dose — measurably higher than semaglutide's number, in a similar population ^[7]. A head-to-head observational comparison published in JAMA Internal Medicine in 2024 reproduced the gap in real-world EHR data ^[8]. SURMOUNT-4 (maintenance), SURMOUNT-CN (Chinese cohort), and the SUMMIT trial for heart failure with preserved ejection fraction extend the data into specific populations ^[9]. A separate NEJM trial in 2024 reported tirzepatide's effect on obstructive sleep apnea in adults with obesity ^[10]. The point is not that tirzepatide is universally better — it is more effective on average, with a similar side-effect profile, often at higher cost and more variable insurance coverage.

The 2025 systematic review. The Annals of Internal Medicine published a systematic review of GLP-1 receptor agonists in adults without diabetes that aggregated the available RCTs and concluded the efficacy and safety profile for chronic weight management is now established, with the caveats this page documents below ^[11]. It is the cleanest single citation when a reader asks "what do the trials actually say overall."

This section will look different within months. The drugs and trials in the field as of November 2026:

Oral GLP-1s, scaled. Novo Nordisk launched its Wegovy pill (oral semaglutide reformulated for chronic weight management) in the US in January 2026. The company reported on June 7, 2026 that the drug crossed three million US prescriptions in its first five months — "one of the strongest US pharmaceutical launches by volume on record," in its own framing ^[12]. Eli Lilly's Foundayo (orforglipron) launched on April 9, 2026, into a market Novo had a three-month head start in. Foundayo's distinguishing feature is that it is a small molecule rather than a peptide — that lets Lilly skip the dietary restrictions Novo has to carry on the Wegovy pill label. Lilly says ACHIEVE-4 safety data supports a planned type 2 diabetes indication filing later this year ^[2].

Duals, triples, and the next-generation entrants. Boehringer Ingelheim and Zealand's survodutide (GLP-1 / glucagon dual agonist) read out a 16.6% weight-loss number in phase 3 in late April 2026 ^[13]. Eli Lilly's retatrutide (GLP-1 / GIP / glucagon triple agonist) produced 25.0% mean weight loss at 80 weeks in its pivotal TRIUMPH-1 trial, published in the New England Journal of Medicine on 29 September 2026 ^[19], and in October beat Ozempic 2 mg on blood sugar and weight in a head-to-head trial in type 2 diabetes. It is not approved, and no application has been filed. Novo Nordisk's CagriSema (semaglutide plus cagrilintide) is in late-stage development. Smaller entrants — Structure Therapeutics, BrightGene, and ecnoglutide (cleared in China for weight loss in March 2026) — are filling specific niches. The competitive structure of this market is changing fast enough that any "best provider" or "best drug" call has a shelf life of months, not years.

What the pipeline does not change. The class-level mechanism (GLP-1 receptor agonism, plus or minus GIP, glucagon, or amylin co-agonism) is the same one the original drugs use. Side-effect profile, weight-regain pattern after discontinuation, and the maintenance-therapy framing are all carried over. A patient who could not tolerate semaglutide because of nausea is unlikely to tolerate the next dual agonist, either.

The literature has matured enough to name the signals that should be on a prescribing physician's checklist. None of these is a reason to avoid the class — but each is a reason to discuss before starting, and each has shaped what an honest review of any GLP-1 provider should say.

Gastrointestinal. Nausea, vomiting, and constipation are common across the class. They are usually dose-related and improve with slow titration. A 2024 Lancet Gastroenterology & Hepatology review covers the mechanism and the management in detail ^[14].

Gallbladder and biliary disease. A 2022 JAMA Internal Medicine meta-analysis reported elevated risk for gallbladder and biliary disease with GLP-1 receptor agonist use compared with placebo or active comparators ^[15]. Absolute risk is small; the effect is consistent enough to warrant counseling, especially for patients with prior gallbladder pathology.

Thyroid carcinogenic risk. The drug labels carry a boxed warning for medullary thyroid carcinoma based on rodent data. The 2024 IJMS systematic review concluded the human signal is unproven but unresolved, and the contraindication for patients with personal or family history of medullary thyroid cancer or MEN-2 syndrome remains in the label ^[16].

NAION (non-arteritic anterior ischaemic optic neuropathy). A 2025 Acta Ophthalmologica review and several case-series papers describe an association between semaglutide use and NAION, a rare eye condition that can cause sudden vision loss ^[17]. The association is not yet causal but has prompted ophthalmology professional bodies to add it to differential diagnoses in patients on semaglutide.

Muscle mass and body composition. Roughly a quarter to a third of weight lost on GLP-1 therapy comes from lean tissue rather than fat, depending on the trial and the population. A 2024 Circulation editorial frames the question — adaptive or maladaptive — and points at resistance training and adequate protein as the two evidence-supported countermeasures ^[18]. Pharmaceutical sponsors (Lilly, Regeneron, others) are running trials of activin-pathway inhibitors as adjunct therapies; none has approval yet. For the 2026 trial evidence behind those proportions, and why the same argument is now used to sell both protein shakes and peptides, see our report on GLP-1 muscle loss.

Many of the telehealth providers PeptideWellness covers in our reviews sell GLP-1 weight-loss programs in some form — compounded, branded, or both. Eight are in our GLP-1 Price Index as of November 2026: Eden, Henry Meds, Hims, Maximus, Mochi Health, Ro, TeleZenMD, and TrimRx. The provider overview page is the directory; each review carries our honest read on pricing, pharmacy partner, prescriber transparency, and where we'd be cautious.

What to ask a provider, regardless of which one: which entity actually compounds the product they ship, and under which legal pathway (503A patient-specific, or 503B outsourcing-facility); whether the molecule is the base form or a salt; whether the provider is currently on FDA's warning-letter list; and what happens to your prescription if the 503B bulks-list exclusion is finalized. Our news coverage of the June 2026 enforcement wave details the four claim patterns FDA flagged and the legal framework behind them.

That list is not the market, and is not meant to be. A review here has to be read by a clinician and has to say something a reader could not work out alone, so it stays deliberately short while the cash-pay market keeps growing. Two places give the wider view of what things cost: our own GLP-1 Price Index, which normalises the larger providers' published prices to an all-in monthly figure with capture dates, and PeptidesToGo, which lists sellers by molecule with the price each publishes to start.