FDA must regulate stem cell therapies to mitigate risks to patients and the public

In December 2025, the US Food and Drug Administration’s (FDA’s) Center for Biologics Evaluation and Review (CBER) approved a gene-based stem cell therapy for Wiskott–Aldrich syndrome, a rare and life-threatening genetic disease. This decision was appropriately based on data from two clinical studies that demonstrated a clinical benefit. Unfortunately, this standard of evidence, and FDA approval itself, are not the norm for many stem cell therapies. Instead, hundreds, if not thousands, of clinics have made unproven and unapproved stem cell treatments widely available to treat everything from common sports injuries to neurological diseases.

Researchers and the public should be wary of potential FDA changes to policies regulating unproven stem cell therapies. Image credit: Science Source/ARTUR PLAWGO.

Officials from the FDA and other federal agencies have tried to stop this potentially dangerous trade. As part of those efforts, the FDA filed two lawsuits in 2018 against clinics involved in the online promotion of unapproved stem cell therapies. After years of court filings and appeals, the agency won an important court case in late 2024 that confirmed the FDA’s power to regulate unproven stem cell therapies. In October 2025, the US Supreme Court declined to reconsider the decision, meaning that after seven years, the FDA had confirmed its regulatory authority over a burgeoning online industry.

That’s good news for proponents of evidence-based medicine. But for how long will this position hold? This may depend in significant part on the current leadership at the Department of Health and Human Services (HHS), which sits above the FDA. Thus far, the signs are not good. Since Congress’ February 2025 confirmation of Robert F. Kennedy, Jr. (RFK Jr.) as Secretary of HHS, changes in the FDA’s senior officials and policy priorities suggest that the FDA may back away from exercising the authority to regulate this important field, despite its seven-year battle to do so. Here, we highlight the changes that the current Administration might consider for FDA regulation of stem cell therapies and the potential fallout for patients and public health—a scenario that’s emblematic of the larger, troubling “medical freedom” movement. While riddled with uncertainty, the current conditions make one thing clear: Now is the time for the public and advocacy organizations to make their voices heard. If not, we are likely to see more patients being diverted from evidence-based care to unproven stem cell treatments with a significant risk of harm.

Despite significant underreporting of adverse events, research has identified hundreds of patients who have suffered physical injury and/or emotional and financial harm from unproven stem cell treatments.

Warning Signs

Within a month of starting as HHS Secretary, RFK Jr. hosted a roundtable to discuss loosening regulations on stem cells. In September 2025, the FDA released new draft guidance on the expedited review of regenerative medicine therapies (which include stem cell therapies). The guidance outlines various accelerated pathways for review and approval. These actions portend the loosening of stem cell regulations (1) and raise the prospect of further deregulating stem cell therapies at a time when the FDA’s current regulatory framework is already inadequate to protect patients (2–5).

In 2021, an estimated 2,750 stem cell clinics in the United States offered unapproved injections of adult stem cells to treat everything from orthopedic injuries and neurodegenerative conditions to cardiovascular disease (2). A 2020 study found pervasive misinformation on clinic websites, with 96% displaying at least one misstatement and each website showing, on average, between four and five misstatements (6).

Despite significant underreporting of adverse events, research has identified hundreds of patients who have suffered physical injury and/or emotional and financial harm from unproven stem cell treatments (3). It’s common to charge patients anywhere from $1,200 to $50,000 for these therapies—often in the guise of participating in a clinical trial (2, 4).

Flawed Oversight

The FDA oversees adult stem cell treatments under its Human Cell, Tissue, and Cellular and Tissue-Based Product (HCT/P) program, which integrates several overlapping authorities over biological products, drugs, devices, and infectious diseases (5). The HCT/P framework consists of three tiers of oversight that apply based on a product’s risk.

The FDA did little to enforce HCT/P requirements against stem cell clinics until 2015, when FDA officials described a “worrisome” lack of evidence for many uses of stem cell therapy. During the first Trump Administration, then-FDA-Commissioner Scott Gottlieb announced plans to ramp up enforcement against clinics promoting high-risk treatments. At the same time, the agency initiated a three-year enforcement policy, during which it would suspend wider enforcement to encourage clinics to work with the FDA to improve compliance. Few clinics did so, and the policy formally expired during the Biden Administration (5). Scientific and legal experts have criticized the FDA for inconsistently and ineffectively enforcing its regulations (5).

Even when the FDA does warn a clinic to improve compliance (a relatively rare event), the clinic can quickly dissolve and reinvent itself as a reincorporated entity. This ease and frequency of shapeshifting led Peter Marks, then-Director of the FDA’s CBER, to describe the enforcement landscape as “a game of whack-a-mole” (5).

Enforcement against stem cell clinics faces additional obstacles. FDA officials must persuade the Department of Justice to initiate litigation, since the agency cannot do so itself (7). Suing for violations of HCT/P regulations forces courts into deep and convoluted rabbit holes of defining what qualifies as “homologous use” for harvested cells and what types and degrees of processing do or do not constitute “more than minimal manipulation.” Resource constraints make inspections infrequent and can limit follow-up to warning letters, with only the occasional lawsuit.

A Path Forward—But Obstacles Remain

To improve compliance, the FDA could cooperate with the Federal Trade Commission (FTC), which exerts oversight over promotion and marketing. Such an approach could streamline enforcement because FTC lawsuits rely on the accuracy of promotional claims instead of the scientific complexity that pervades the FDA’s risk-based HCT/P framework. The promise of leveraging FTC enforcement was demonstrated in FTC v. Peyroux and Regenerative Medical Group, Inc. (2018), wherein the FTC and the state of Georgia sued a clinic for online promotion of unproven stem cell treatments (8). Within one week of the complaint’s filing, the clinic agreed to comply with agency requirements and pay $525,000.

Unfortunately, the prospect of greater FDA (or FTC) intervention runs against declining judicial deference to agency decisions and the new Administration’s skepticism of regulation and scientific expertise. The FDA’s starting point for regulating stem cell treatments is to require formal premarket review and approval for high-risk therapies. But with his vow to end the “aggressive suppression” of stem cell clinics that promote unapproved therapies, RFK Jr. upends the FDA’s logic by tolerating the risk of unsafe or ineffective products reaching the market.

Should it wish to pursue a goal of shielding stem cell clinics from regulatory oversight, it might use any one or all of the following four strategies. First, and most directly, current HHS leadership can attempt to cease FDA enforcement—a serious incursion on the agency’s authority, but potentially within the legal authority of the head of HHS. Second, the Secretary wields heavy influence in naming candidates for FDA Commissioner, selecting senior leadership of its various centers and offices, and populating the FDA’s many advisory committees. For instance, in June 2025, the new HHS Secretary removed all 17 members of the Centers for Disease Control and Prevention’s (CDC’s) Advisory Committee on Immunization Practices (ACIP) and replaced them with advisors aligned with the HHS’s decision to emphasize the low and often speculative risk of vaccine-induced injury over the well-documented risk of vaccine-preventable diseases (9).

HHS might prefer a third approach with more staying power, such as narrowing the FDA’s interpretation of statutory terms like “drug,” “device,” and/or “biological product” or implementing comparable changes to regulatory definitions of “more than minimal manipulation” or “homologous use.” Expanding regulatory exemptions in this way could have a long-term impact on the FDA’s medical product oversight because deregulatory changes, which can endure through the comings and goings of agency leadership, require resources and political capital to undo. Fourth, whether by design or default, stem cell regulation will likely (if not inevitably) wane because the Administration’s structural changes, including mass layoffs and decimated staff morale, have diminished the regulatory capacity of an agency that was already seriously underresourced (10).

Deregulation of fringe treatments goes hand-in-hand with skepticism of modern medical interventions.

Beyond the new Administration’s changes and the FDA’s potential strategies for pulling back on stem cell regulation, clinic- and manufacturer-initiated litigation could imperil the FDA’s modest enforcement efforts. The US Supreme Court’s recent elimination of “Chevron” deference to agency legal interpretations (11, 12) invites regulated entities to sue when aggrieved by an agency’s action. More fundamentally, litigants might question the FDA’s basic authority to regulate HCT/Ps by invoking the Court-created “major questions doctrine” (13, 14), which requires clear congressional authorization of agency actions on matters of “vast economic and political significance” (15). If so, current HCT/P regulation might be in jeopardy since Congress did not expressly authorize the FDA to define, categorize, and regulate HCT/Ps. Rather, the FDA constructed the HCT/P framework piecemeal from its authorities over infectious disease, drugs, devices, and biologic products. Some courts have already second-guessed the FDA’s interpretation of the term “drug” as too broad—even though the text, FDA practice, and public health have long supported the FDA’s interpretation here. Two federal appeals courts have recently sided with the FDA’s view that the stem cell therapies in those cases were drugs and thus subject to HCT/P regulations. Win or lose, however, the substantial costs of litigating these issues (in time, money, attorney hours, and more) are more likely to inhibit, rather than incentivize, regulation and enforcement.

A Troubling “Medical Freedom” Movement

HHS’s potential liberalizing the use of stem cell therapies is part of a larger, disturbing pattern in Americans’ relationship with modern medicine. Deregulation of fringe treatments goes hand-in-hand with skepticism of modern medical interventions. Americans reporting “a lot” of trust in physicians and hospitals dropped from 72% to 41% from 2020 to 2024 (16). Only 40% of American adults think vaccinating their children is “extremely important” as of 2024 (17). RFK Jr. has fed this skepticism, despite exacting research on the evidence behind vaccines and mass childhood vaccination campaigns that enabled the CDC to declare measles “eliminated” in 2000. From January 1 to December 10, 2025, there were 47 outbreaks of measles and 1,544 confirmed cases, causing the United States to topple a 25-year record for the most cases in a single year (18). The new Administration’s FDA has furthered vaccine skepticism in many ways (19), including by “upend[ing] core policies governing vaccine development.” According to 12 former FDA commissioners, the FDA is changing the vaccine regulatory standard to “a substantially higher and more subjective approval bar” based on unreliable evidence of vaccine deaths in 10 children (20).

As vaccine expert Peter Hotez (21) has explained, the medical freedom movement combines reduced government oversight of “sensationalized cures” with increased skepticism of modern medicine, such as vaccines. The movement has resurrected age-old arguments that “the government has no business meddling in personal health decisions” (22)—an ideology that leaves little room for public health agencies like the FDA (23). In addition to stoking vaccine hesitancy, medical freedom advocates have championed expanded access to stem cell therapies, raw milk, and dietary supplements (21, 24). About 60% of US adults take dietary supplements, despite their questionable benefits and lack of FDA approval (25).

The Regulator’s Dilemma

During his confirmation hearing, RFK Jr. correctly attributed the public’s dwindling trust in the FDA to growing concerns that the agency is ineffective and subject to improper financial influence by outside interests. HHS’s efforts to restore public confidence by reducing regulatory oversight is more than counterintuitive; it is dangerous. Waning confidence in the FDA’s mission and competence increases the need for effective and enforceable regulations that support the agency’s scientific credibility (26, 27). These regulations should govern the FDA–industry relationship to mitigate concerns of capture, foster evidence-based interventions for serious health conditions, and hold accountable the growing number of stem cell clinics that use misinformation to convince unwitting patients to undergo high-cost and high-risk treatments offering dubious, if any, therapeutic benefits. As an article by Rand et al. (28) states, “While being a trustworthy agency cannot guarantee the public’s trust, [it] builds a groundwork for public trust.”

The new Administration’s appetite for dismissing scientific evidence (29–31) portends significant turmoil for the FDA’s regulation of stem cells—and HCT/Ps more broadly. In response, the medical profession and the public should file petitions and publicly urge the FDA to improve its oversight of stem cell therapies. And they should urge Congress through letter-writing, petitions, and social media to strengthen the agency by providing adequate funding and the appropriate authority and expertise for protecting the public from unproven stem cell therapies that have already diverted too many patients from evidence-based care.