503A vs 503B Compounding Pharmacies: What GLP-1 Patients Need to Know

What is the difference between a state-licensed pharmacy and an outsourcing facility?

A state-licensed pharmacy compounder is a licensed pharmacist in a state-licensed pharmacy, or a physician, working under the pharmacy compounding provisions of the Food, Drug, and Cosmetic Act [2]. State boards of pharmacy have primary responsibility for day-to-day oversight of those pharmacies, and FDA also conducts surveillance and for-cause inspections of them [2].

An outsourcing facility is a separate category created in 2013 by the Drug Quality and Security Act [2]. These facilities register with FDA, are inspected by FDA on a risk-based schedule, and are subject to current good manufacturing practice (CGMP) requirements, which state-licensed pharmacies are not [2]. FDA publishes a table naming the facilities that have registered as outsourcing facilities [5].

Can outsourcing facilities currently compound semaglutide or tirzepatide from bulk substances?

Not under current FDA conditions. FDA states that outsourcing facilities are restricted from compounding with a bulk drug substance unless the substance is on the bulks list, which identifies substances with a clinical need, or meets another condition FDA sets, and that tirzepatide and semaglutide do not currently meet those conditions [1].

In April 2025 a federal district court denied a preliminary injunction request regarding compounded semaglutide, and FDA said it did not intend to act on certain outsourcing-facility violations until May 22, 2025 [1].

On 2026-04-30 FDA proposed to exclude semaglutide, tirzepatide and liraglutide from the outsourcing-facility bulks list, finding no clinical need for outsourcing facilities to compound them from bulk substances [3]. Comments were due 2026-06-29, and FDA said no final decision had been made [3].

Can a state-licensed pharmacy still compound semaglutide or tirzepatide?

The drug product must be compounded for an individual patient based on receipt of a prescription, and the compounder may not compound, regularly or in inordinate amounts, drugs that are essentially copies of a commercially available product [1]. FDA may consider a compounded product essentially a copy when it uses the API (active pharmaceutical ingredient) of a commercially available product in the same, similar or easily substitutable strength and that product can be used by the same route, unless a prescriber documents a significant difference for an identified patient [1].

FDA gives semaglutide combined with vitamin B12 as an example that may be considered essentially a copy when the route is the same and the strengths are within 10% of the commercially available products, unless a documented significant difference applies [1]. FDA also said it does not intend to act against a compounder for compounding a copy regularly or in inordinate amounts if the compounder fills four or fewer prescriptions of that product during a calendar month [1].

FDA also said that, for state-licensed pharmacies compounding semaglutide injection, the period of enforcement discretion has ended [1].

What does FDA say about quality and safety of compounded GLP-1 drugs?

Compounded drugs are not FDA-approved, and FDA does not verify their safety, effectiveness or quality before they are marketed [2]. Poor compounding practices can result in contamination or a drug that contains too much or too little active ingredient, which FDA says can lead to serious patient injury and death [2].

Adverse events have been reported. As of 2026-05-31, FDA had received 990 adverse event reports for compounded semaglutide and more than 730 for compounded tirzepatide, along with reports of dosing errors [1].

FDA notes that compounded GLP-1 medications may come in vials containing multiple doses for a patient to draw up. It recommends using vials of sterile medication containing multiple doses within 28 days of first use, because contamination risk rises after that, and using a new sterile needle and syringe for each dose [4]. FDA states that compounded drugs should only be used in patients whose medical needs cannot be met by an FDA-approved drug [4].

Do the published trial results apply to compounded versions?

The weight-loss figures usually quoted for semaglutide and tirzepatide come from clinical trials. In STEP 1, 1,961 adults with obesity or overweight and no diabetes received semaglutide 2.4 mg or placebo for 68 weeks: mean weight change was -14.9% versus -2.4% [6]. In SURMOUNT-1, 2,539 adults received tirzepatide 5, 10 or 15 mg or placebo for 72 weeks: -20.9% at 15 mg versus -3.1% with placebo [7]. FDA does not verify the safety, effectiveness or quality of compounded drugs before they are marketed [2].

What about retatrutide and cagrilintide?

FDA states that retatrutide and cagrilintide cannot be used in compounding under federal law, are not components of FDA-approved drugs, and have not been found safe and effective for any condition [4].