FDA Closes the Compounding Loophole: Empower Pharmacy Faces Dual Enforcement Threat on GLP-1 Copies

FDA Issues Warning Letter to Empower Pharmacy Over Insanitary Conditions and Illegal Compounding

The FDA has issued a warning letter to Empower Clinic Services, operating as Empower Pharmacy, following an inspection in November 2025. The agency found that the Houston-based compounding pharmacy was preparing, packing, or holding sterile products under "insanitary conditions," which could lead to contamination. Furthermore, Empower was found to be compounding tirzepatide and semaglutide products that appear to be "essentially copies" of FDA-approved drugs like Eli Lilly's Mounjaro/Zepbound and Novo's Ozempic/Wegovy. This violates Section 503A of the Federal Food, Drug and Cosmetic Act, which prohibits compounding copies of commercial products regularly or in inordinate amounts. The FDA also questioned the validity of prescriber determinations of "significant difference" for these compounded drugs. Empower has 15 working days from the September 18, 2026, warning letter date to respond to the violations.

• FDA inspectors identified "insanitary conditions" at Empower Pharmacy's Houston site during a November 2025 inspection. These conditions were severe enough to potentially contaminate sterile products, rendering them "injurious to health." The FDA deemed Empower's subsequent response to these concerns, initially communicated via a Form 483, as unsatisfactory due to "gaps and discrepancies" in the submitted paperwork. This highlights a critical public health risk associated with the pharmacy's manufacturing environment.
• Empower Pharmacy was cited for failing to comply with Section 503A of the Federal Food, Drug and Cosmetic Act, specifically for compounding tirzepatide and semaglutide products that are "essentially copies" of FDA-approved commercial drugs. These include Eli Lilly's Mounjaro and Zepbound, and Novo's Ozempic and Wegovy. The law prohibits pharmacists from regularly or excessively compounding copies of commercially available products, suggesting Empower's manufacturing volumes and product similarities were deemed pretextual by the FDA.
• The FDA raised concerns about the legitimacy of "significant difference" determinations provided by prescribers for Empower's compounded products. Evidence suggested that some orders lacked these determinations, while others featured verbatim, potentially pre-generated statements across numerous records. The agency also questioned the individualized nature of these determinations when generated via third-party technology platforms offering pre-selected menu options, indicating a systemic issue in justifying the compounding of these drugs.

The Established Safety Profile of Approved Tirzepatide and Semaglutide

Both tirzepatide and semaglutide carry well-characterised safety profiles across their studied indications, with gastrointestinal (GI) adverse events representing the predominant tolerability concern for each agent. Evidence from phase 3 trials, real-world studies, and meta-analyses consistently supports a broadly manageable safety landscape, though meaningful differences exist between and within drug classes.

• Gastrointestinal adverse events dominate for both agents. In SURPASS-4, nausea (12–23%), diarrhoea (13–22%), decreased appetite (9–11%), and vomiting (5–9%) were more frequent with tirzepatide than with insulin glargine (nausea 2%, diarrhoea 4%, decreased appetite <1%, vomiting 2%); most cases were mild to moderate and occurred during dose escalation. Across the SUSTAIN and PIONEER phase IIIa programmes, GI disorders were reported in 41.9% of patients receiving subcutaneous semaglutide and 39.1% receiving oral semaglutide, versus 22.0% and 24.8% with comparators, with prevalence highest during initiation and escalation phases.

• Hypoglycaemia risk is substantially lower with tirzepatide than with insulin glargine, particularly in sulfonylurea-naïve patients. In SURPASS-4, the proportion of participants experiencing hypoglycaemia (glucose <54 mg/dL or severe) was 6–9% with tirzepatide versus 19% with glargine overall, narrowing further in participants not on sulfonylureas (tirzepatide 1–3% vs. glargine 16%). No major hypoglycaemia episodes were reported in the phase 2 semaglutide dose-finding study, and hypoglycaemia rates were similar between semaglutide and comparators across the SUSTAIN and PIONEER pools.

• Cardiovascular safety has been established for both agents. In SURPASS-4, adjudicated MACE-4 events (cardiovascular death, myocardial infarction, stroke, hospitalisation for unstable angina) occurred in 109 participants and were not increased with tirzepatide versus glargine (hazard ratio 0.74, 95% CI 0.51–1.08). Across the SUSTAIN and PIONEER CVOTs, subcutaneous semaglutide demonstrated a reduced risk of major adverse cardiovascular events versus placebo, while oral semaglutide met non-inferiority criteria.

• Cholelithiasis and biliary complications represent a class-level signal for semaglutide. Cholelithiasis incidence was higher with both subcutaneous and oral semaglutide versus placebo in the SUSTAIN and PIONEER programmes. In a meta-analysis of subcutaneous semaglutide in obesity without diabetes, serious adverse events — predominantly GI and hepatobiliary disorders including acute pancreatitis and cholelithiasis — were 1.6 times more likely with semaglutide (RR 1.60, 95% CI 1.24–2.07, p=0.0003). A published case report further describes a rare cascade of concurrent diabetic ketoacidosis, acute pancreatitis, and ruptured acalculous cholecystitis in a patient receiving weekly subcutaneous semaglutide 1 mg, raising the question of whether GLP-1 receptor agonist–mediated biliary stasis may predispose to complex biliary complications under severe physiological stress.

• Real-world head-to-head data indicate comparable overall tolerability between semaglutide and tirzepatide, with agent-specific differences in adverse event profile. In a nationwide multicenter study of 2,549 patients with obesity, at least one adverse event occurred in 50.9% of the semaglutide group and 51.0% of the tirzepatide group (p=0.524). However, musculoskeletal and allergic reactions were more common with tirzepatide, onset of GI and neuropsychiatric symptoms occurred earlier with tirzepatide, and pancreatic events leading to discontinuation were more frequent with semaglutide (p=0.006).

• Discontinuation rates and dose-dependent tolerability are relevant considerations at higher doses. In a network meta-analysis of non-diabetic adults with obesity, the highest odds of treatment discontinuation due to adverse events were observed with semaglutide MTD (OR 7.36, 95% CI 2.56–21.15) and tirzepatide MTD (OR 5.56, 95% CI 2.28–13.58), with GI side effects more common at higher-dose regimens for both agents. In a real-world comparison of oral versus injectable semaglutide formulations, adverse events occurred more frequently with oral semaglutide (16.7% vs. 4.9%), and discontinuation due to adverse events was also more common in the oral group.

Evolution of the Obesity Treatment Landscape Over Five Years

The past five years have seen a marked shift in the obesity pharmacotherapy landscape, driven by the clinical validation of incretin-based agents across multiple large randomized controlled trials. Subcutaneous semaglutide, a once-weekly GLP-1 receptor agonist, established a strong efficacy benchmark in nondiabetic adults with overweight or obesity, producing a mean percentage body weight reduction of -11.85% versus placebo (95% CI: -12.81 to -10.90; P < .00001) across four RCTs involving 3,613 participants, alongside significant improvements in waist circumference, BMI, and cardiometabolic risk factors including blood pressure and lipid profiles. Tirzepatide, a first-in-class dual GIP/GLP-1 receptor agonist, subsequently raised the efficacy ceiling further: meta-analyses of six RCTs in nondiabetic individuals with overweight or obesity demonstrated a mean percentage body weight change of -16.32% (95% CI: -18.35 to -14.29) and an absolute weight reduction of -13.95 kg (95% CI: -18.83 to -9.07) versus placebo, with a clear dose-response relationship (meta-regression β = -0.72% per 1 mg increase; p = 0.0014). The SURMOUNT program further confirmed marked and durable weight reduction with tirzepatide, with clinically relevant improvements in waist circumference, blood pressure, triglycerides, and inflammatory biomarkers.

Beyond weight reduction, the field has increasingly focused on cardiovascular and cardiorenal outcomes as primary endpoints, reflecting a broader repositioning of obesity therapies as integrated cardiometabolic interventions. In nondiabetic adults with obesity, GLP-1 receptor agonists reduced MACE risk by 32% (RR 0.68; 95% CI: 0.53–0.87; P = 0.002), while tirzepatide demonstrated a 59% reduction (RR 0.41; 95% CI: 0.18–0.92; P = 0.03) in this population. In obesity-related HFpEF specifically, the SUMMIT trial showed reductions in worsening heart failure events and improvements in health status with tirzepatide, supporting a phenotype-specific role in heart failure management. SURPASS-CVOT established cardiovascular safety for tirzepatide in type 2 diabetes by demonstrating noninferiority versus dulaglutide for 3-point MACE in patients with established atherosclerotic cardiovascular disease, further reinforcing confidence in the class across metabolic phenotypes.

The emergence of oral formulations and novel non-peptide agents has added a new competitive dimension to the landscape. Oral semaglutide 25 mg, evaluated in OASIS 4, demonstrated significantly greater percentage body weight loss compared with orforglipron 36 mg — a non-peptide GLP-1 receptor agonist evaluated in ATTAIN-1 — with mean differences of -3.2 percentage points (95% CI: -5.9, -0.4; treatment-regimen estimand) and -3.0 percentage points (95% CI: -5.8, -0.3; efficacy estimand) in population-adjusted indirect treatment comparisons. Tolerability differences were also notable: discontinuation due to any adverse event favored oral semaglutide (OR 4.1; 95% CI: 1.3, 13.0 for orforglipron), as did discontinuation due to gastrointestinal adverse events (OR 13.9; 95% CI: 2.0, 96.0). Across the class, gastrointestinal adverse events — principally nausea, vomiting, diarrhea, and constipation — remain the predominant tolerability concern, with real-world data indicating differential GI profiles among agents; semaglutide was associated with lower odds of abdominal pain, nausea, vomiting, and gastroparesis compared with dulaglutide and liraglutide in a cross-sectional analysis of 10,328 adults in the NIH All of Us cohort.

Beyond Obesity: Expanding Indications for Tirzepatide and Semaglutide

Both tirzepatide and semaglutide are being investigated across a broadening range of indications beyond obesity, reflecting growing interest in the pleiotropic effects of incretin-based therapies. The trials below span metabolic, cardiovascular, renal, neurological, and sleep-related disease areas, employing rigorous randomised controlled designs.

FDA Cracks Down on Compounding: Safety and GLP-1 Market Impact

The recent FDA warning to Empower Pharmacy represents a significant moment in the ongoing dialogue surrounding compounding pharmacies and the integrity of the pharmaceutical supply chain. At its core, this action underscores the critical importance of patient safety, particularly when it comes to sterile preparations. The finding of 'insanitary conditions' is not merely a procedural violation; it echoes historical tragedies where contaminated compounded drugs led to widespread outbreaks of severe infections, including fungal meningitis and bacterial endophthalmitis, with devastating consequences for patients. Such conditions inherently elevate the risk of microbial contamination, which can result in serious adverse health outcomes.

Beyond safety, the FDA's focus on Empower's compounding of tirzepatide and semaglutide as 'essentially copies' of approved GLP-1 receptor agonists highlights a crucial regulatory boundary. While compounding serves a vital role in meeting specific patient needs, it is not intended to circumvent the rigorous approval process for commercially available drugs, especially when no clinical justification for a 'significant difference' exists. This practice not only undermines the regulatory framework designed to ensure drug quality and efficacy but also creates a parallel market for unregulated versions of popular medications. Patients using these compounded versions may face risks related to inconsistent potency, purity, and stability, potentially leading to dosing errors or unexpected adverse events, as real-world data for tirzepatide already indicate a high incidence of incorrect dose administration and injection-site reactions even with approved products.

This enforcement action signals a renewed commitment by the FDA to ensure that compounding pharmacies operate within their intended scope and adhere to fundamental safety and quality standards. For the broader pharmaceutical landscape, it reinforces the value of FDA-approved therapies and may help to mitigate the proliferation of unregulated alternatives, ultimately guiding patients and healthcare providers toward safer, more reliable treatment options.