Levi Pasikov

Associate Editor

Loyola University Chicago School of Law, JD 2028

There is a substance that looks like a drug, functions like a drug, and is marketed like a drug, yet it generally exists outside the United States Food and Drug Administration’s (FDA) traditional regulatory framework. Peptide drugs are everywhere, but regulation is nowhere to be found. These synthetic chemicals manipulate a wide range of biological processes in the human body, making them increasingly attractive for therapeutic, cosmetic, and performance-enhancing functions. But leaving peptides largely outside the FDA’s traditional framework creates a regulatory gap that warrants immediate federal oversight.

Nature’s messengers, medicine’s next frontier

Peptides are short chains of amino acids—the fundamental building blocks of proteins—that occur naturally in the body and perform a variety of biological functions. By binding to specific cellular receptors, peptides act as signaling molecules that regulate vital functions such as hormone activity, immune defense, tissue growth, and digestion. Advances in biotechnology have enabled scientists to chemically synthesize peptides for therapeutic use, harnessing their biological activity to treat disease and improve health outcomes. Today, peptide-based products are marketed for a range of purposes, including weight loss, muscle growth, tissue repair, and a reduction of visible aging.

Scientists and chemists have identified more than 7,000 peptides in the human body, expanding the potential for therapeutic development. Yet therapeutic potential does not establish safety. Of the 137 peptide drugs tracked by the FDA, only 54 are FDA-approved, 9 were approved and then discontinued, and 74 have never received approval. Although FDA approval status does not prevent the continued sale, distribution, and use of unapproved peptide products, it remains an important distinction in evaluating their regulatory and safety status. With non-FDA-approved peptide drugs increasingly obtained through the gray market, concerns regarding regulatory oversight and consumer safety have arisen.

Operation without regulation

In 2023, the FDA banned compounding pharmacies—specialized pharmacies that customize medications for individual patients—from preparing 19 widely used peptide-based products, citing concerns about their safety and limitations based on available evidence. To counter this measure, suppliers began operating outside the established drug-approval pathways to avoid the required clinical stages of research, manufacturing controls, and post-market obligations. These “underground” operations created what is now known as the gray market, an online marketplace consisting of direct-to-consumer websites, research-chemical vendors, informal online communities, international suppliers, and social media-linked sellers. Gray market vendors advertise peptides with disclaimers such as “for research purposes only” or “not for human consumption,” yet consumers partake. The resulting complication in regulatory oversight raises questions about whether current safeguards adequately protect individuals who obtain these products for personal use.

In July 2026, the FDA’s Pharmacy Compounding Advisory Committee (FDA Pharmacy Committee) considered recommending seven peptide-based substances for inclusion on a list governing bulk drug substances—pharmaceutical ingredients in their raw chemical form—that may be used in compounding pharmacies. The FDA Pharmacy Committee voted in favor of recommending six of the seven peptides. However, FDA-backed scientists opposed the decision to include the formerly unapproved peptides, citing insufficient research. Another concern for the FDA scientists was the precedent set by the approval. Approving these peptides allows an avenue for FDA approval without being subject to the strict FDA approval process. It should also be noted that 6 of the 12 members on the FDA Pharmacy Committee also represent companies that offer peptide therapy and have a financial stake in the matter. Additionally, the FDA Pharmacy Committee will further consider five more peptides for compound pharmacy approval before March 2027.

Safety in the shadows

Safety remains one of the most significant concerns surrounding the expanding unapproved peptide market.  Although FDA-approved peptide drugs have undergone the rigorous safety testing required by the FDA, the peptide products that are sold through the gray market lack comparable clinical evidence, including roughly zero evidence in human trials. Moreover, doctors have voiced concerns regarding the purity of these chemicals. Unapproved peptide-based products, which are not subject to the safety requirements of FDA-approved drugs, limit consumers’ ability to verify whether a product contains its intended contents, or instead harmful contaminants. This opens the possibility of manufacturers adulterating the substances with other medication or even heavy metals—a practice used by many black-market illicit drug suppliers.

The absence of human clinical trials and long-term empirical data makes it difficult to characterize the full range of potentially adverse effects associated with many unapproved peptides. Additionally, limited documentation of the effects of non-FDA-approved peptide-based drugs is not equivalent to evidence of safety, but rather uncertainty.

A prescription for uncertainty

The future of peptide regulation remains uncertain, but the direction of the current debate suggests that expanded access may precede the development of adequate safety guardrails. Recent efforts have been made to incentivize the FDA to take a stronger stance on mandatory peptide research and regulation. Yet, the FDA’s recent committee developments permitting the compounding of additional peptide substances raise important concerns and major issues about their regulatory approach. The committee’s recommendations warrant scrutiny in light of potential conflicts of interest. Commercial bias in decisions affecting public access and safety should not be tolerated in federal regulation. Additionally, expanding access through compounding pharmacies does not eliminate the underlying evidentiary gap, but instead prioritizes availability over consumer protection.

Unless the FDA takes the appropriate actions to break this cycle, the peptide market will remain trapped in a regulatory Catch-22: the absence of sufficient safety standards impedes meaningful oversight, while the lack of meaningful oversight allows peptide products to proliferate without adequate safety requirements. The most likely consequences are not a dramatic public health crisis, but rather a continued expansion of peptide use in the mainstream market without resolving questions concerning product safety. Ultimately, the FDA should seek to ensure that expanded access to peptide therapies is accompanied by meaningful safeguards, rather than treating access and safety as competing objectives.