The double standard: why stem cells yes and peptides no?

The uncomfortable question

Try a thought experiment. One patient tells you he injects a peptide bought online. Another tells you she traveled to a clinic to receive umbilical cord cells for $30,000. Which one gets the lecture? In most practices, the first. The second usually gets a curious question: did it work?

This article does not set out to defend a vial or attack a cell. It aims at something more modest and perhaps more irritating: applying the same yardstick to both. Because when the data are placed side by side, the peptide does not come off worse. On several lines it comes off better.

Two yardsticks

Start with scrutiny. In July 2026, the FDA Pharmacy Compounding Advisory Committee devoted two days of meetings to seven peptides, with an agency technical document for each one³. The votes were close: 8–6 for BPC-157, KPV and TB-500, and 7–5 for MOTS-c, without constituting approval or demonstrated clinical benefit⁴. The FDA also keeps BPC-157 on its list of substances that may present significant safety risks, citing possible immunogenicity and impurities⁵. All documented in what the FDA actually said.

Now, stem cells. In 2016 an analysis in Cell Stem Cell already documented widespread promotion of unapproved interventions by US businesses¹⁷. By March 2021 there were 1,480 businesses operating 2,754 clinics, more than four times the number identified five years earlier¹⁶. In Panama, researchers from the Gorgas Institute and the National Research Bioethics Committee (CNBI) counted at least six companies at the end of 2025; 100% offered packages with procedures, hotel, transport and tourist activities, for $5,000 to $50,000, promoted on Instagram, YouTube and Facebook⁶. The CNBI sent at least six notifications to the Ministry of Health between 2015 and 2025, and the authors concluded: “The lack of enforcement by regulatory bodies has probably facilitated the growth of this unproven industry in Panama”⁶.

A peptide goes through a federal committee and comes out with an 8–6. A cell goes through a travel agency and comes out with a tour package. Which of the two has been examined more rigorously?

The approval scoreboard

If the question is which therapeutic class has proven more, the answer leaves little room for debate. Since insulin, more than 80 peptide drugs have reached the market¹. Semaglutide, a peptide, was associated in SELECT with a 20% reduction in the composite of cardiovascular death, nonfatal myocardial infarction or nonfatal stroke in 17,604 adults with established cardiovascular disease and overweight or obesity but without diabetes (HR 0.80)². More context in the peptide universe.

On the cell side, the FDA itself sums it up: on its April 2024 page, the only stem cell products approved in the US were blood-forming cells derived from umbilical cord blood, approved only for disorders of the hematopoietic system¹⁰; its official list includes nine cord blood products⁹. (The agency classifies separately, as gene therapies, products made from the patient's own genetically modified hematopoietic stem cells, such as Casgevy or Zynteglo, which also appear on that list⁹.) In December 2024 the first mesenchymal stromal cell therapy was added, for steroid-refractory acute graft-versus-host disease in children¹¹. The agency states that no regenerative therapy is approved for knee pain, autism, Parkinson's disease, ALS or COPD, and warns: “if you are being charged for these products or offered these products outside of a clinical trial, you are likely being deceived and offered a product illegally”¹⁰.

The harm file

Here the asymmetry becomes striking. In the New England Journal of Medicine, three patients suffered severe bilateral vision loss after intravitreal injections of adipose-derived “stem cells” at a US clinic; after one year, their visual acuity ranged from 20/200 to no light perception¹². The same journal published a glioproliferative lesion of the spinal cord as a complication of “stem-cell tourism”¹³, in a patient who had received injections in China, Mexico and Argentina and whose lesion originated from the implanted cells¹⁵.

In 2018 the CDC described 12 patients in Texas, Florida and Arizona with infections after receiving bacterially contaminated cord blood-derived products; all were hospitalized and none died¹⁴. A review from the same year compiled 35 cases of complications or death after unproven interventions, and its authors warn that the figure probably underestimates the problem¹⁵. In Panama, the CNBI warned in August 2026 of documented risks such as thromboembolism, fibrosis, cell growth with tumor potential, severe vision loss and even deaths⁷.

And research peptides? A 2025 systematic review of BPC-157 found no human clinical safety data¹⁸. That is not a certificate of safety: it is a silence, and the FDA points to theoretical risks such as immunogenicity⁵. The most publicized event was RAADfest in 2025: two women hospitalized in critical condition, requiring intubation, after injections at a conference booth run by a physician without permission to practice in Nevada; both recovered¹⁹²¹. The Nevada Pharmacy Board could not determine the cause, because it was unable to test the product, and in February 2026 it fined three people, including a physician and a pharmacist without permission to practice in Nevada, and the group accused of mailing the peptides, $5,000 to $10,000 each²¹. One file holds case series in the NEJM and a CDC report; the other, a data vacuum and one serious episode tied to unlicensed practice. Neither is reassuring. But only one of them causes panic.

Equally legal, equally gray

In Panama, Executive Decree 179 of 2018 recognizes hematopoietic transplantation as the only application with proven evidence; any other use must take place within approved research protocols⁶⁸. The National Directorate of Pharmacy and Drugs has not registered advanced therapy products with stem cells for other uses⁷, and in 2026 the Ministry of Health inspected two establishments and opened administrative proceedings against them⁸. Law 419 classifies “marketing a product without sanitary registration” as a very serious offense²⁰.

It is not our place to issue legal rulings; that is what the physician's legal map in Panama and, above all, a lawyer are for. But the question imposes itself: if the unregistered peptide vial and the off-protocol cell infusion inhabit similar gray zones, why does one cause a scandal at the physicians' dinner table while the other is advertised in tourism magazines? Local details are in stem cells in Panama.

Why we forgive the cell

What follows is opinion, not evidence. We offer four hypotheses.

• The aura of the self. “They are your own cells” sounds like natural medicine, even when the product has been processed, cultured or comes from someone else's cord.
• The set design. Scrubs, an operating room, a marble reception desk: the hospital setting lends a legitimacy the product has not earned.
• Price as argument. What costs $30,000 looks serious; what costs $80 looks suspicious. Behavioral economics is not pharmacology.
• Bad company. Peptides entered public conversation alongside the gym, the influencer and the online store. Stem cells arrived alongside the academic laboratory and bone marrow transplantation. Both deserve to be judged by their data, not by their friends.

One yardstick

The proposal is not to lower the bar for peptides, but to apply it evenly. Three questions, for any product that goes into a patient: what human evidence exists for this indication? what guarantees the quality of this lot? can its origin be traced? By that yardstick, much of the unapproved stem cell market struggles: the FDA warns of cross-contamination and of products not tested for infectious diseases¹⁰, and the CDC notes that cord blood cannot be decontaminated after collection¹⁴.

That is where peptides can win. A peptide is a synthetic molecule of known sequence whose identity and purity can be verified in the laboratory lot by lot; the documented problem is not the molecule but the product's origin, as discussed in what is really in the vial. And the class has already shown, with more than 80 approved drugs, that it knows how to pass the exam¹. The full arguments of its supporters are in The other side. A single standard is not a threat to peptides. It is their best opportunity.