FDA's New Wave of Compounded GLP-1 Warning Letters (2026)

For two years, the conversation about GLP-1 weight management drugs focused on shortages and demand. In 2026 the conversation has shifted to enforcement. The U.S. Food and Drug Administration (FDA) has made the promotion of compounded GLP-1 products one of its most visible compliance priorities, and Health Canada is running a parallel campaign north of the border. For pharmaceutical, telehealth, and natural health product companies, the lesson is the same. Marketing claims are now a primary inspection target, and a single misleading statement can put a product, and a company, in the regulator's sights.

This article breaks down what the FDA did in June 2026, the legal theory behind it, the safety record driving the crackdown, the Canadian parallels, and the practical steps a compliance team should take now. At MF License & Regulatory Consultants (MFLRC), we help regulated companies build promotional review and quality systems that hold up under exactly this kind of scrutiny.

What happened in June 2026?

During the week of June 15, 2026, the FDA issued 25 warning letters to telehealth companies for making false or misleading claims about compounded GLP-1 products. The agency also published two new web resources that spell out, in plain language, which promotional claims it considers illegal. This was a coordinated return to enforcement after a quieter spring.

The letters came from the Office of Prescription Drug Promotion (OPDP) within the Center for Drug Evaluation and Research (CDER), the same office that polices prescription drug advertising. Alongside the letters, the FDA launched a dedicated page, FDA to Telehealth Companies: What to Know When Promoting Compounded Drugs, and a companion page, FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. Together they read like a compliance checklist of what not to do.

CDER leadership reinforced the point publicly, stressing that compounded GLP-1 products are not FDA-approved and have not gone through the review for safety, efficacy, and manufacturing quality that the agency requires for drugs cleared through the New Drug Application (NDA) or Abbreviated New Drug Application (ANDA) pathways. The takeaway for industry is that the FDA is watching promotional content across every channel, including websites, social media, and affiliate marketing.

Three enforcement waves in under a year

The June action is not a one-off. Since September 2025, the FDA has released compounded drug and direct-to-consumer advertising warning letters in coordinated batches rather than a steady trickle. Quiet periods should not be read as a change in priorities.

Enforcement wave	Approximate date	Volume	Primary focus
First major batch	September 2025	About 80 warning letters and 40 untitled letters	Launch of a broad crackdown on direct-to-consumer drug advertising
Second batch	February 20, 2026 (made public March 3, 2026)	30 warning letters	Telehealth marketing of compounded GLP-1 products
Third batch	Week of June 15, 2026	25 warning letters	Telehealth marketing of compounded GLP-1 products

Across late 2025 and early 2026, the FDA issued 58 letters that specifically addressed compounded GLP-1 products such as semaglutide and tirzepatide, along with other compounded products like sildenafil and tadalafil. More broadly, the agency has sent thousands of letters warning drug and telehealth firms to remove misleading ads over a six month span, more than it sent over the entire preceding decade. The FDA news release announcing the 30 February letters called it a new era of promotional enforcement.

Why compounded GLP-1 drugs draw special scrutiny

Compounded drugs are not FDA-approved. The agency does not review them for safety, effectiveness, or quality before they are sold, and they are not the same as generic drugs, which are approved. When marketing blurs that line, the FDA treats the product as misbranded. Understanding the compounding framework explains why the GLP-1 category is so exposed.

Compounding is meant to fill genuine patient needs, for example when a patient cannot use an FDA-approved drug or the approved drug is not commercially available. During the GLP-1 shortages, large volumes of compounded semaglutide and tirzepatide entered the market. Those shortages have since resolved. The FDA declared the tirzepatide shortage over in December 2024 and the semaglutide shortage over in February 2025, then set wind-down dates for mass compounding.

Two legal categories matter here. Section 503A pharmacies compound for an identified patient based on a prescription. Section 503B outsourcing facilities can make larger batches but must follow current good manufacturing practice (cGMP). The table below summarizes the difference.

Feature	503A compounding pharmacy	503B outsourcing facility
Basis for compounding	Patient-specific prescription	Can compound larger batches without a patient-specific prescription
Manufacturing standard	State pharmacy practice standards	Current good manufacturing practice (cGMP)
FDA approval of the product	Not FDA-approved	Not FDA-approved
Adverse event reporting to FDA	Generally not required by federal law	Required to report to FDA
GLP-1 status after shortage	Only for a documented individual medical need, not a copy of the approved drug	No clinical need identified; proposed for exclusion from the 503B bulks list

The FDA has gone further. In 2026 it proposed to exclude semaglutide, tirzepatide, and liraglutide from the 503B bulks list, finding no clinical need for outsourcing facilities to compound them from bulk substances. The public comment period on that proposal runs through late June 2026. The agency has also made clear that the salt forms semaglutide sodium and semaglutide acetate are different active ingredients than the approved drug and have no lawful basis for use in compounding, and that retatrutide and cagrilintide cannot be used in compounding at all. For most companies, the realistic path forward is to stop copying approved GLP-1 drugs and to fix how any remaining products are marketed.

The promotional claims the FDA is targeting

The core legal theory is misbranding under section 502(a) of the Federal Food, Drug, and Cosmetic Act, supported by the prescription drug advertising provisions in section 502(n). The FDA evaluates the overall net impression a website or advertisement creates, not just individual sentences. The agency's own telehealth page lists the claims it considers false or misleading:

Using branding that falsely implies the telehealth company is the compounder when it is not.
Describing a compounded drug as a generic version of an FDA-approved drug. Generic drugs are approved before marketing; compounded drugs are not.
Claiming or implying that a compounded drug is FDA-approved or has been evaluated for safety and effectiveness.
Describing a compounded drug as clinically proven to produce the same result as the approved drug.
Claiming a compounded drug is sourced from an FDA-approved or FDA-licensed pharmacy or outsourcing facility. The FDA does not approve or license facilities in that way.
Using exact same active ingredient phrasing in a way that implies sameness with the brand-name product.

The safety record behind the crackdown

The FDA is not only concerned about words. It points to a growing safety signal. As of May 31, 2026, the agency had received 990 adverse event reports for compounded semaglutide and more than 730 for compounded tirzepatide, more than 1,700 reports combined. Because state-licensed pharmacies that are not outsourcing facilities are generally not required to report adverse events, the FDA believes the true number is underreported.

The agency has flagged several specific risks with compounded and unapproved GLP-1 products:

Dosing errors. Patients and even some health-care professionals have measured or calculated incorrect doses, in some cases leading to hospitalization.
Doses beyond the approved label. Reports describe larger single doses, more frequent dosing, or faster titration than the approved product allows.
Salt forms. Some products use semaglutide sodium or acetate, which are not the active ingredient in the approved drug.
Cold-chain failures. Injectable GLP-1 drugs need refrigeration, yet some compounded products have arrived warm or with inadequate ice packs.
Counterfeits and fraud. The FDA has identified counterfeit Ozempic and fraudulent compounded products labelled with pharmacies that did not make them or that do not exist.
Research use loopholes. Some sellers label products for research purposes or not for human consumption, then sell them to consumers with dosing instructions.

To protect the supply chain, the FDA established a green list import alert (66-80) to stop GLP-1 active pharmaceutical ingredients with potential quality concerns from entering the country, while still allowing imports from manufacturers that meet its standards. The safety record is the backdrop that makes the promotional enforcement so aggressive.

What this means in Canada

Canadian companies should not treat this as a purely American story. Health Canada is running a parallel crackdown, and Canada's rules on prescription drug advertising are stricter than those in the United States. The enforcement logic is nearly identical: protect patients from unauthorized products and from claims that make those products look approved.

In a public advisory updated on January 21, 2026, Health Canada warned that unauthorized and counterfeit GLP-1 products are being sold in Canada, both in stores and online. The advisory notes that some websites and social media ads misuse official Health Canada logos and display fake endorsements. Health Canada says plainly that selling unauthorized or counterfeit products, or making false or misleading claims to prevent, treat, or cure illness, is illegal in Canada. The department is responding with seizures and compliance and warning letters against both the sale and the advertisement of these products, and is working with the Canada Border Services Agency to stop unauthorized shipments.

The authorized GLP-1 drugs themselves are legitimate. Semaglutide products such as Ozempic, Rybelsus, and Wegovy and tirzepatide products such as Mounjaro and Zepbound are authorized by Health Canada to treat type 2 diabetes and obesity, and each carries an eight-digit Drug Identification Number (DIN). In Canada, only licensed pharmacies can legally sell prescription drugs, and compounding cannot be used to mass-produce a copy of a commercially available approved drug. Provincial pharmacy regulators have instructed pharmacies not to compound semaglutide for weight loss, and compounded versions often rely on unregulated peptide powders sold as research chemicals, which sit outside the quality controls that apply to authorized products.

Canada's advertising rules add another layer. Under section C.01.044 of the Food and Drug Regulations, prescription drugs may be advertised to the general public only with respect to name, price, and quantity. Fuller product claims are reserved for health-care professionals. Health Canada permits only reminder messages and help-seeking messages to consumers, and the Pharmaceutical Advertising Advisory Board (PAAB) and Ad Standards Canada review promotional material for compliance. Section 3 of the Food and Drugs Act further restricts advertising to the public for the treatment of certain serious diseases. A claim that would draw an untitled letter in the United States could be a clear violation in Canada.

The competitive landscape is about to change as well. Novo Nordisk's regulatory exclusivity for semaglutide in Canada ended on January 4, 2026, and Health Canada is reviewing multiple generic applications, with generics possible around mid-2026. As lower-cost authorized options arrive, accurate comparative and equivalence claims will matter more than ever, and regulators will be watching how those products are promoted.

Promotional issue	United States	Canada
Lead regulator	FDA (OPDP within CDER)	Health Canada, with PAAB and Ad Standards review
Core rule	Misbranding under FD&C Act sections 502(a) and 502(n)	Section C.01.044 of the Food and Drug Regulations; section 3 of the Food and Drugs Act
Consumer claims for Rx drugs	Allowed but heavily policed for net impression	Name, price, and quantity only; reminder and help-seeking messages
Compounded copies of approved drugs	Not permitted once shortage resolves	Treated as unauthorized manufacturing
Enforcement tools	Warning and untitled letters, import alerts	Seizures, compliance and warning letters, border action

What companies should do now

Whether you sell a compounded product, an approved drug, or a natural health product, the safest assumption is that every public-facing claim could be read by a regulator tomorrow. The companies that weather this enforcement cycle are the ones that can prove each claim before it goes live. A strong promotional compliance program rests on a few pillars.

Build a medical, legal, and regulatory review process

Route every piece of promotional content through a documented medical, legal, and regulatory (MLR) review before publication. That includes websites, landing pages, social posts, email campaigns, and any material created by affiliates or influencers on your behalf. Keep dated approval records so you can show who reviewed what and when.

Substantiate every claim

For each claim, keep an evidence file that links the statement to the data behind it. If you cannot support a comparative or clinical claim with reliable evidence, do not make it. Avoid generic, FDA-approved, clinically proven, and same as language unless it is accurate and substantiated.

Review the net impression, not just the words

Read each page the way a consumer would. Branding, imagery, and layout can imply approval or sameness even when the text is careful. Make sure nothing on the page suggests your company is the compounder, or that a product is approved or licensed, when it is not.

Put the quality unit in the loop

Sourcing and label claims are quality claims. The quality unit should sign off on statements about manufacturing, ingredients, and supply chain, and should verify that any product description matches the actual approved status and source. This is where promotional review and quality assurance meet.

Control sourcing, training, and monitoring

Map your supply chain and confirm that ingredient and sourcing language is accurate. Train marketing teams and any telehealth or affiliate partners on what they may and may not say. Then monitor the market, keep a change log, and maintain a correction and recall plan so you can act quickly if a claim needs to come down.

Promotional compliance checklist

Use this checklist as a starting point for a self-assessment of your GLP-1 or compounded product marketing:

Every public claim is reviewed and approved through a documented MLR process.
No content states or implies that a compounded product is FDA-approved, Health Canada approved, or a generic.
No content describes a compounded product as clinically proven to match an approved drug.
Branding does not imply your company is the compounder unless it is.
Sourcing language does not claim an FDA-approved or FDA-licensed facility.
Each comparative or clinical claim is backed by an evidence file.
Prescription drug advertising to Canadian consumers is limited to name, price, and quantity.
The quality unit has reviewed all sourcing, ingredient, and label claims.
Affiliate, influencer, and partner content is governed by the same standards.
A correction, takedown, and recall plan is documented and ready to use.

Common mistakes to avoid

Treating compounded products as interchangeable with approved drugs in marketing copy.
Assuming a quiet enforcement period means the risk has passed.
Letting marketing publish claims without regulatory or quality review.
Relying on affiliates or telehealth partners without controlling their messaging.
Using the word generic or implying FDA or Health Canada approval to build trust.
Ignoring the Canadian rules when selling into Canada from a U.S. platform.
Failing to keep substantiation records that prove each claim.

Frequently asked questions

What is a compounded GLP-1 drug?

A compounded GLP-1 drug is a version of a medicine like semaglutide or tirzepatide that a pharmacy or outsourcing facility prepares, rather than the finished product made by the original manufacturer. Compounded drugs are not FDA-approved or Health Canada authorized, which means they are not reviewed for safety, effectiveness, or quality before they reach patients.

Why did the FDA send warning letters if compounding is legal?

Compounding under section 503A or 503B can be lawful, but the FDA's concern is promotion, not the act of compounding. The warning letters target marketing that makes a compounded product look FDA-approved, generic, or equivalent to an approved drug. That marketing can make the product misbranded under the Federal Food, Drug, and Cosmetic Act.

Are compounded semaglutide and tirzepatide legal in Canada?

Authorized semaglutide and tirzepatide products with a Drug Identification Number are legal and sold through licensed pharmacies. Compounding to mass-produce a copy of an approved drug is treated as unauthorized manufacturing, and provincial regulators have told pharmacies not to compound semaglutide for weight loss. Health Canada is actively acting against unauthorized and counterfeit GLP-1 products.

What is the net impression standard?

Net impression is the overall message a piece of promotion sends, taking branding, images, layout, and wording together. Under this standard, even technically accurate statements can be misleading if the page as a whole leads a consumer to believe a compounded product is approved or equivalent to an approved drug.

What is the difference between a 503A pharmacy and a 503B outsourcing facility?

A 503A pharmacy compounds for a specific patient based on a prescription and follows state pharmacy standards. A 503B outsourcing facility can make larger batches without patient-specific prescriptions but must follow current good manufacturing practice and report adverse events to the FDA. Neither produces an FDA-approved product.

What should we do if we receive a warning letter?

Respond within the timeframe stated in the letter, usually 15 working days. Take down or correct the cited claims immediately, document a root cause analysis, and put corrective and preventive actions (CAPA) in place so the problem does not recur. A regulatory consultant can help you draft a response that the agency will accept and prevent further escalation.

How MFLRC can help

MF License & Regulatory Consultants helps pharmaceutical, telehealth, natural health product, and weight management companies turn enforcement risk into a managed process. Our senior consultants have more than 20 years of experience across pharmaceutical and natural health product regulation in Canada, the United States, and Europe. We provide:

Advertising and promotional compliance review against FDA, Health Canada, and PAAB standards, including net impression assessments.
Claims substantiation support, so each comparative and clinical statement is backed by an evidence file.
Quality unit and quality system oversight that links sourcing and label claims to your quality assurance program.
Gap assessments, SOP development, and warning letter response and CAPA support.
Licensing and regulatory affairs guidance for Canadian and cross-border market entry.

If your team markets GLP-1, weight management, or any compounded or regulated product, a promotional and quality review now is far cheaper than a warning letter later. To see how the same principles play out in inspections, read our related article on quality assurance versus compliance in healthcare.

Book a Consultation with MFLRC

Conclusion

The June 2026 warning letters confirm a pattern that is now hard to ignore. The FDA, supported by a parallel effort from Health Canada, has made the promotion of compounded GLP-1 products a sustained enforcement priority. The agencies are drawing a bright line between compounded and approved drugs, and they expect companies to respect it in every claim, image, and web page. Treat promotional review and quality oversight as core compliance functions, substantiate what you say, and watch the net impression your marketing creates. Companies that build that discipline now will be ready for the next wave, whenever it lands.