Their fans use them to boost energy, strength, performance and healing, and to slow the aging process. They also use them to feel better than well, if there is such a thing. Why wouldn’t you want to try them?
Dr. Dhruv Khullar, a specialist in hospital medicine and an associate professor in the departments of medicine and population health sciences at Weill Cornell Medicine, has a great deal to say on the subject. In fact, he reported on peptides in his most recent article in The New Yorker—he doubles as a world-class medical journalist—and it’s well worth a look-see.
Dr. Khullar covered their popularity. He reviewed their theoretical benefits but also their demonstrated and potential harms. And he mounted a convincing argument against their use before proper study of their safety and efficacy.
What are peptides?
Peptides are short-chain amino acids. They generally have 50 or fewer amino acids per chain. More than 50 make it a full-fledged protein.
Quite a few peptides have been turned into drugs over the years. The best-known and most widely used among these are insulin and GLP-1, or glucagon-like peptide-1. Insulin has been used to treat diabetes for a little over a century, while GLP-1, a relative newcomer, has been tested and retested in humans, proving safe and effective for weight loss and weight-related conditions.
But peptide enthusiasts have other substances in mind; peptides that are under-researched, unregulated, and unproven for the purposes their sellers advertise.
What’s driving their use?
The medical freedom movement
It’s normal for people to want control over their bodies and their health, Dr. Khullar wrote. But is good health simply a matter of consumer choice?
One physician influencer recently said, “As long as it doesn’t ‘hurt’ them, they should be able to choose.” But meaningful choice requires good data, and without a system that requires that medical products are demonstrated to be safe and effective, we often won’t get it.
If you have a terminal illness, and there’s no approved treatment for it, it makes a lot of sense for people to have a chance to try an experimental drug. But widespread use of untested drugs in the general population is a different matter.
Health risks
Some scientists are concerned that unapproved peptides could lead to potential immune reactions and growth of cancerous cells in people who use them.
In animal studies, the peptide TB-500 was seen to speed up the growth of dormant tumors. Another popular peptide known as BPC-157 was banned by the Anti-Doping Agency in 2022. It hasn’t been approved for human use by any global regulatory authority, yet thousands continue to buy it on the grey market.
Dr. Khullar explained that BPC-157 seems to stimulate the production of nitric oxide, which “enhances blood flow and reduces certain forms of inflammation.” However, the peptide also generates free radicals—highly reactive, unstable oxygen molecules that create oxidative stress, with resulting damage to cell membranes, proteins and DNA. BPC-157 also promotes angiogenesis, the creation of new blood vessels. Cancerous tumors make use of that very process to feed their growth. That’s a reason for caution when it comes to BPC-157 use.
Clear harms
Dr. Khullar also described a striking example of harm. At last year’s Revolution Against Aging and Death Festival in Las Vegas, two women received peptide injections. Shortly thereafter, he wrote, “they developed elevated heart rates, swollen tongues, and trouble breathing. By the time they reached the hospital, one of them had lost control of her neck muscles, and the other had been intubated. Both were ultimately connected to ventilators.”
In addition to the risks and harms posed by peptides themselves, a portion of them have serious anomalies when it comes to their purity, sterility or dosage, according to a spokesperson from a company that tests them.
The evidence, please
Anecdotal evidence isn’t the kind scientists rely on as they conduct their research. Anecdotes are stories we tell each other. When amplified on social media, they may seem to amount to something greater, but that is not the case.
During the clinical research process, researchers investigate a variety of causes for a drug candidate’s effects on a symptom or set of symptoms that characterize a particular disease or condition. Central to the process is the placebo effect. Is the drug comparable to an inert substance, like a sugar pill? Might study participants merely imagine that the drug is working? That’s a very common experience. The drug is considered efficacious if it outperforms the placebo.
Some peptide users could be experiencing the placebo effect. Might a person’s sense that a peptide is working actually be traced to a protein shake, a rewarding interaction with a friend or even a good night’s sleep? A well-structured clinical trial would be able to provide preliminary answers to these questions. Additional trials would be able to confirm them.
Who benefits?
The need for regulation
During the 1930s, an antibiotic called elixir sulfanilamide gave patients “intense pain, kidney failure, and neurological problems,” Dr. Khullar wrote. After more than 100 people died, Congress passed the Federal Food, Drug, and Cosmetic Act of 1938, authorizing the FDA to evaluate a medical product’s safety before it could be sold.
Then, in 1962, when thalidomide—a sedative prescribed for pregnant women—led to birth defects in thousands of babies around the world, the 1938 Act was modified. Drug manufacturers would need to conduct controlled trials to ensure their products weren’t just safe but effective.
The FDA has operated along these lines ever since, until very recently. As Dr. Khullar expressed in his New Yorker article, “It is becoming possible to imagine a future in which American regulators lose their grip on the safety and efficacy of drugs,” thanks to widespread distrust of authority and expertise.
The scientific consensus
One prominent physician-scientist based at UCLA, Dr. Pinchas Cohen, discovered a peptide called humanin that was part of “junk DNA.” Junk DNA, it turns out, isn’t junk at all. It contains instructions for numerous peptides and proteins that had never been studied, Dr. Khullar explained, quoting Cohen as follows: “This is not a dozen or so things you can buy at the gym. This is a revolution in science. It’s going to start a new era of drug discovery.”
Dr. Cohen’s prediction may well come to pass, but in the meantime, people shouldn’t take peptides until they’re deemed safe and their effects are fully understood. That’s the message Dr. Khullar, and most of the experts cited in his article, aimed to convey.