The FDA Should Not Allow Untested Peptides to Be Added Into Patients’ Medications

The U.S. Food and Drug Administration (FDA) will convene a Pharmacy Compounding Advisory Committee (PCAC) July 23rd and 24th to discuss whether seven peptides manufactured by Chinese firms should be added to the FDA’s 503A Bulks List—a “positive list” of bulk drug substances (active pharmaceutical ingredients) that state-licensed compounding pharmacies are legally permitted to use in patient-specific prescriptions. Approving these untested substances, which have been found by the FDA’s own scientists to present significant health and safety risks, could prove to legitimize a Chinese gray market while allowing potentially dangerous substances to be included in American medicine.

Peptides constitute a broad grouping of substances, described simply as chains of amino acids. While several synthetic peptides have been FDA-approved, such as tirzepatide, which serves as the active ingredient in GLP-1s, there are a score of other peptides that are largely experimental. These substances have been touted by health influencers across the Internet for their supposed, yet usually unproven, health benefits, including antiaging, muscle growth, and enhanced immune function. 

Should the FDA authorize the seven peptides being discussed to possibly be added to the 503a Bulk List, it would allow these peptides to be produced by compounding pharmacies. Compounding pharmacies create customized medications for patients with unique medical needs, such as patients with allergies to specific substances or patients who require unique dosages of treatments. Compound pharmacies were allowed to produce FDA-approved peptides from 2002 to 2025 to combat a GLP-1 shortage in the United States. But now that the shortage has ended, compound pharmacies no longer have the legal basis to produce them.

Moreover, information on the risks of compounding peptides has emerged. Compounding may result in additional additives being included in medicines, untested formulations being used, different chemical structures, and dosing errors, as they lack the same critical oversight that mainstream manufacturers provide. As such, it’s unsurprising that poison control centers have seen a 15-fold increase in the number of calls related to injected GLP-1 drugs. Many of these calls have been related to dosing errors that are easier to make with compounded drugs. 

The seven peptides PCAC is discussing July 23–24 are substantially produced with active ingredients largely sourced through an online Chinese gray market, and several of the chemical firms producing these ingredients have been involved in illegal fentanyl precursor production. The sale of these peptide active ingredients occurs largely online and with cryptocurrency, and, as such, avoids regular oversight and accountability. This lack of accountability can translate to dangerous impurities in substances, including product degradation, incorrect protein sequences, and even the inclusion of dangerous heavy metals and contaminants. (Heavy metals such as lead can disrupt cellular function, and others like manganese can accumulate in the brain, leading to neurotoxicity.) Compound pharmacies lack the capability to detect these defects and ensure the adequate handling and storage of these ingredients in the substances they purchase from suppliers.

What’s more, in a great many cases, the true sources of the suppliers are unknown, further muddying what is known about this peptide supply chain. Should a patient be harmed taking these gray-market drugs, there is little potential for recourse. This is particularly concerning given that a 2026 survey of 1,000 U.S. peptide users found that gray-market peptide buyers (e.g., people finding peptides on social media and online platforms) are three times more likely than users who acquired peptides from the regular pharmacy system to visit the emergency room.

If the FDA adds these seven peptides to its 503A Bulks List, it would be legitimizing this Chinese gray-market and allowing unvetted foreign drug suppliers unfettered access into the U.S. market. And beyond the concerns about the source of the peptide ingredients, there are concerns about the final peptides themselves. Four of the seven peptides being discussed have no human safety studies at all, while the other three have just a small number of dated and poorly controlled preclinical animal studies. Moreover, two of these peptides, BPC-157 and TB-500, have been potentially linked to cancer. For this reason, the FDA’s own scientists, after reviewing all seven peptides, recommended against listing all of them on the Bulks List.

Several FDA officials have also expressed concerns about possible conflicts of interest, as the administration has appointed individuals to serve on the committee who have connections to the peptide industry. Six members of the PCAC panel either currently work for peptide-related businesses, have worked for peptide-related businesses in the past, or have promoted the use of peptides publicly. Meanwhile, above them, Health and Human Services Secretary Robert F. Kennedy Jr. has repeatedly championed peptides, stating that he’s used them personally and has experienced a “really good effect.” He has also spoken out against the supposed suppression of peptides by the FDA in the past and has said he seeks to end this suppression as secretary.

Though the PCAC’s endorsement does not guarantee that these seven peptides will be added to the 503a List, it does pave the way for their approval. It also signals a retreat from evidence-based pharmaceutical decision-making by the FDA. By ignoring the recommendations of qualified scientists, the FDA could actively endanger patients across the country.

The FDA should not allow compounding pharmacies to produce and sell unapproved and untested drugs to the American public.