Some FDA-approved GLP-1s are being studied in clinical trials for the disease, but their results aren’t available yet. Experts caution against using experimental peptides for Long COVID.
Key points you should know:
- Peptides, short chains of amino acids that can have drug-like effects, are booming in popularity — even though many have not been thoroughly studied in humans and are not Food and Drug Administration–approved.
- Despite the lack of research, some medical clinics and providers are advertising peptides as Long COVID therapies, and they are often hyped up on social media.
- GLP-1 medications are also peptides. Some people with Long COVID are “microdosing” them in hopes of treating their symptoms.
- One clinical trial is assessing the GLP-1 tirzepatide for the disease, while the National Institutes of Health RECOVER program will launch a trial on semaglutide later this year. A third clinical trial is assessing larazotide, a synthetic peptide, for Long COVID in children.
- Research on peptides and Long COVID is ongoing. Experts say it’s safest to wait for those results, or at least to use peptides under the care of medical professionals.
This past spring, Anca Vrîncianu, a 24-year-old living in Romania, reached her breaking point. Over the course of about a year, her Long COVID symptoms had progressed such that she was all but bedbound. Doctors had recommended a series of treatments that didn’t help, so she turned to Reddit.
Through that search, she learned about the peptides MOTS-c and KPV, which some posters claimed could help with energy production and gut health, respectively. In Romania, as in the U.S., these peptides are not approved for medical use — but Vrîncianu was able to order them online anyway, thanks to a web of suppliers capitalizing on the booming interest in peptides. She wasn’t worried about the risks. “I didn’t have much to lose,” she said.
Several months later, Vrîncianu continues to use peptides, along with B vitamins, probiotics, and other therapies. It’s hard to say how much peptides, specifically, have helped, since she’s experimenting with multiple things at once. Her regimen, including peptides, “didn’t cure me by any means,” Vrîncianu said. “But they did at least bring me some sort of relief after being so hopeless.”
Her story is, for better or worse, a common one. With no drug specifically approved to treat Long COVID and medical care for the disease often lacking, many people turn to untested methods to manage their symptoms. Increasingly, that includes peptides, which are gaining prominence not only through social media, but also medical clinics and wellness websites explicitly pitching these compounds as Long COVID therapeutics. But they haven’t been approved or thoroughly studied for that purpose, raising concerns among medical providers.
Without safety and efficacy data, no one knows exactly how peptides affect the body. They might help with Long COVID symptoms, but might also worsen them — as some people have already reported from personal experience — or cause entirely new health problems, said Eric Topol, a cardiologist and director of the Scripps Research Translational Institute in California.
And since many peptides are not approved for medical use, people often buy them from largely unregulated sources; sometimes, peptides are even sold as “research chemicals” not technically meant for human use. That means people can’t be confident that what’s on the label is actually what’s in the vial, or that the substance hasn’t been contaminated or mixed with something else — further raising the possibility of unintended and potentially dangerous side effects.
In this anything-goes market, “I don’t think it’s wise for people with Long COVID, or anyone for that matter,” to take the risk of trying unapproved peptides, Topol said. Research on peptides and Long COVID is in progress, including some conducted by Topol. But at the moment, marketing hype is outpacing science.
“It’s just not right,” Topol said. “They are marketing to Long COVID when there’s no reasonable evidence whatsoever” — and patients may pay the price.
In this anything-goes market, “I don’t think it’s wise for people with Long COVID, or anyone for that matter,” to take the risk of trying unapproved peptides, Topol said.
What even are peptides?
Peptides are short chains of amino acids, the building blocks that make up proteins. The body naturally makes many types of peptides, but synthetic versions can also be produced in a lab. Peptides bind to receptors on cells, instructing them to carry out specific actions within the body.
The category is incredibly broad, spanning naturally occurring hormones, well-studied and approved GLP-1 diabetes and weight-loss drugs such as Ozempic, and a wide array of experimental compounds with alphabet-soup names like BPC-157, TB-500, MOTS-c, and KPV. Marketing materials for these and other peptide compounds promise they can improve athletic training, heal injuries, boost energy, tan the skin, and almost anything else you can imagine. Demand for these unapproved compounds has exploded in recent years.
Into this milieu come clinics and providers suggesting that peptide therapies can improve various Long COVID symptoms. The Sick Times found multiple examples of healthcare providers, medical clinics, and wellness websites explicitly describing various unapproved peptides as Long COVID treatments. Among other claims, these sources said peptides can reduce inflammation, boost energy, improve mental health, repair damaged tissue, regulate the immune system, and treat cognitive dysfunction.
These promises sound alluring. But when it comes to most peptides, Topol emphasized,“there are no data regarding safety and efficacy” to back up such claims.
The science on peptides and Long COVID
Researchers are trying to gather more data on peptides and Long COVID. Michael Paidas, an OB-GYN and researcher at the University of Miami Miller School of Medicine, is one.
“As soon as [COVID] hit,” he said, “I knew exactly what I wanted to do”: find a way to block the SARS-CoV-2 virus, which causes COVID-19, from entering cells and causing damage to the body.
In pursuit of that goal, Paidas and his colleagues developed what they call SPIKENET, a peptide designed to prevent SARS-CoV-2 from binding to a particular type of receptor found on cells throughout the body. In mouse experiments, SPIKENET has been shown to reverse inflammation, oxidative stress, and tissue swelling among animals infected by another type of coronavirus.
As of now, the research has not progressed beyond animals. Currently, Paidas’s team is conducting additional research on SPIKENET’s pharmacokinetics — that is, how the substance interacts with the body — in animals. That’s “one of the last phases before we develop this for a human application” and conduct clinical trials, he said. “I’m committed to really seeing this through to develop a therapy.”
Elsewhere, researchers from Massachusetts General Hospital are studying larazotide, an oral synthetic peptide, in both children and adults with Long COVID. The research is ongoing, so results aren’t available yet — but researchers hope larazotide can help repair COVID-related damage to the gut, thereby reducing Long COVID symptoms.
I’m committed to really seeing this through to develop a therapy.
Michael Paidas, University of Miami
Meanwhile, Topol and colleagues at Scripps (including The Sick Times’ advisory board member Julia Moore Vogel) are studying the GLP-1 medication tirzepatide, which is sold under the brand names Mounjaro and Zepbound, as a potential treatment for Long COVID symptoms that include fatigue, cognitive dysfunction, pain, and shortness of breath.
Data from the trial won’t be available until late this year or early next year, Topol said, but the idea is that the peptide may improve Long COVID symptoms by reducing inflammation. “It turns out tirzepatide is a very potent anti-inflammatory, both systematically and in the brain,” Topol explained.
The RECOVER-Treating Long COVID initiative, run by the U.S. National Institutes of Health, is also studying GLP-1 medications to better understand their effects on Long COVID. Specifically, the trial will focus on semaglutide, the active ingredient in Ozempic and Wegovy. As of January, enrollment was expected to begin this summer.
The promise and peril of GLP-1s
Some people aren’t waiting around for the results of these studies to try GLP-1s. That includes Joshua*, a 33-year-old with Long COVID who lives in California and asked to use a pseudonym to preserve his medical privacy. Around six months ago, he decided to try microdosing tirzepatide.
There’s not much research on GLP-1 microdosing — that is, taking doses much smaller than those typically prescribed. But some preliminary and anecdotal data suggest this approach may harness the drugs’ benefits, including anti-inflammatory effects, without triggering significant weight loss or gastrointestinal side effects.
To begin microdosing, Joshua sourced the medication through his personal network in Los Angeles. He had reservations, since he’d tried medications in the past that worsened his symptoms. He’d also tried other peptides, which didn’t seem to hurt but also didn’t help. “It was not an easy decision” to take tirzepatide, “but it was kind of a desperate decision,” Joshua said.
Within hours of taking his first dose, Joshua said, he could breathe more deeply and his focus felt sharper. He’s continued taking the medication — now with buy-in from his doctors, whose attitude is “‘If it’s working and it’s not harming you, then go for it,’” Joshua said.
Some people, however, have reported harms from GLP-1s. In an April survey of 120 people with Long COVID or myalgic encephalomyelitis who have taken GLP-1 drugs, 53% said symptoms including cognitive dysfunction, exercise intolerance, and fatigue had improved as a result, while 28% said their symptoms worsened, and the rest felt no change. Those with severe symptoms were less likely to improve and more likely to worsen, compared to people with milder disease. Those data come from a backward-looking survey — not a clinical trial with a placebo group for comparison — but still provide insight into how GLP-1 drugs may affect people with Long COVID.
“About 3 weeks after starting the tirzepatide, I experienced a sudden decline,” with significantly worsened fatigue, muscle weakness, sensory hyper-sensitivity, and more, wrote one person who took the survey. More than four months later, they remained 100% bedbound and had not returned to their pre-tirzepatide baseline of being housebound but able to complete daily activities independently, they wrote.
Other people have reported bad experiences on social media. “I’ve tried about 30 interventions for Long COVID, and this was by far the worst for me,” wrote one Redditor who said they tried microdosing tirzepatide and experienced serious gastrointestinal side effects, dizziness, and insomnia.
Is there any way to safely take peptides for Long COVID?
As these experiences show, people with Long COVID who experiment even with medications that are fully approved by U.S. regulators, albeit not for this disease, sometimes experience negative reactions. GLP-1s have gone through large, peer-reviewed clinical trials involving thousands of people. While research on their long-term effects is ongoing, and they do come with side effects, these medications are widely considered safe, Topol said. Even still, they can be disastrous for people taking them off-label for Long COVID.
Meanwhile, experimental peptides that have not been thoroughly studied or approved fall into a whole different category of risk. In some cases, regulators have specifically raised safety concerns about their use.
In 2023, the U.S. Food and Drug Administration (FDA) forbade compounding pharmacies from making certain peptides — including those now sometimes recommended to people with Long COVID, like BPC-157 and MOTS-c — due to safety concerns, including immune reactions and product impurities that could potentially lead to serious health complications. (Under the Trump Administration, the FDA has taken steps to again allow compounding pharmacies to make these products.) Some researchers have also raised concerns about the potential for some peptides to feed tumor cells.
In 2023, the U.S. FDA forbade compounding pharmacies from making certain peptides — including those now sometimes recommended to people with Long COVID, like BPC-157 and MOTS-c — due to safety concerns, including immune reactions and product impurities that could potentially lead to serious health complications
Given these possibilities, anyone interested in using a peptide would ideally do so under the care of medical professionals, said David Putrino, director of the Cohen Center for Recovery from Complex Chronic Illness at Mount Sinai in New York City. Putrino, who is planning a clinical trial on peptides and chronic knee pain, is more open-minded about peptide use than some clinicians, saying it’s hard to blame anyone with Long COVID for searching for solutions that don’t exist within the mainstream medical system.
But if someone chooses to use experimental peptides, Putrino said, it’s best to work with a care team that can perform regular monitoring, such as through blood tests, to look for warning signs of dangerous complications. Exactly what that monitoring entails would vary by person and what they’re taking, he said. He is “interested in tracking lots of things because [the effects of peptides] are so unknown: inflammatory, vascular health, kidney and liver function, metabolic health, immune function, and thyroid function.”
Given the potential risks, “I just hope people are safe and wise and prudent and doing this under guidance,” Paidas agreed.
Jamie Ducharme is a freelance journalist specializing in health and science reporting. Her coverage of Long COVID won an award from the New York Press Club.
All articles by The Sick Times are available for other outlets to republish free of charge. We request that you credit us and link back to our website.
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