Thinking about peptides? Doctors reveal key dos and don’ts as ‘Wild West’ market grows

The peptide boom is under scrutiny as the FDA weighs easing restrictions on several drugs in the category.

Peptides, which are short chains of amino acids that serve as the building blocks of proteins, have gained popularity among wellness influencers and fitness gurus as a means of building muscle, healing injuries or appearing younger.

Similar to how GLP-1s (glucagon-like peptide-1 agonists) suppress appetite and trigger weight loss, peptides can signal other functions, like the release of growth hormones.

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But unlike GLP-1 drugs — which were extensively studied and regulated — many peptides lack comparable evidence and oversight, said New York endocrinologist Dr. Philip Rabito, adding that some are "not reviewed by the FDA for safety, effectiveness or quality before marketing."

Peptides under FDA review, including BPC-157, are often marketed for tendon and gut healing, injury recovery and inflammation reduction, despite warnings about the risks of unapproved treatments.

Even as regulators consider loosening restrictions, the market has been widely described as a "Wild West," with various versions sold online without a prescription.

In an interview with Fox News Digital, board-certified internist and longevity expert Dr. Amanda Kahn, who prescribes peptides in her own New York practice, confirmed that interest has grown "significantly" across the U.S.

Peptides are popular because they "sit at the intersection of wellness optimization and medicine," according to the doctor.

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"As a class, they are targeted biosimilar molecules that can influence specific pathways like inflammation, recovery and metabolism in a way that feels more biologically synergistic than traditional pharmaceuticals," she said.

Most patients spend a few hundred to thousands of dollars on these drugs per month, according to Kahn. Costs can be high because peptides are often custom-made and must meet strict quality and sterility standards.

"At the same time, patients today are far more proactive and invested in their health," Kahn added. "They’re not waiting to get sick; they want to feel better, recover faster and age more intentionally."

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Peptides have evolved rapidly from just a few years ago, when they were largely focused on weight loss, the expert said, with growing interest in energy, post-illness or injury recovery, muscle preservation and sleep quality.

But these drugs are not one-size-fits-all, experts warn, especially when not prescribed by a professional or cleared by a reputable pharmacy.

Experts shared the following guidance on using peptides.

Kahn recommends using peptides with "a clear, clinical rationale, not just because they’re trending."

"Think of peptides as part of a broader health plan, not a standalone solution," she advised.

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Kahn said patients often come into her practice focused on weight or appearance, but in-depth testing may uncover underlying issues such as inflammation, metabolic dysfunction, hormonal imbalance or recovery deficits.

"It’s both aesthetic and medical, but the trend in my internal medicine practice has always been toward specific health concerns," she added.

Dr. Kent Bradley, chief medical officer at 10X Health in California, recommends approaching peptides with "curiosity and rigor" and discussing the science with a physician.

"Work with a clinician who provides a baseline of biomarkers before you introduce peptides," he recommended during an interview with Fox News Digital. "You will need to know where you’re starting in order to measure the impact."

Peptides should always be purchased from "reputable compounding pharmacies by prescription," Kahn emphasized.

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"While they are powerful signaling molecules, when used appropriately, they can be very safe and effective," she said. "When used incorrectly, [with] the wrong dose, wrong indication or poor sourcing, they can be dangerous or ineffective."

She added, "The key is clinical oversight, proper selection and individualized use."

The current peptide ecosystem — including unlicensed providers and "gray market" access — is "more dangerous than the molecules themselves," Kahn warned.

It's important to use pharmacies that meet FDA 503A or 503B regulations to ensure consumer safety, the expert added.

Multiple peptides should not be combined without understanding how they interact with each other, nor should they be injected as mixtures, Kahn warned.

"Don’t treat them as risk-free supplements," she said. "They are biologically active and should be used thoughtfully."

"Peptides should be cycled, paused and re-assessed — don’t ‘set it and let it go.’"

Dose-response and drug interactions require medical oversight, and peptides should be prescribed by a doctor, according to Bradley. Some products that are marketed as "natural" may still have the capacity to do harm to the body, he warned.

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Fundamental pillars of health, like sleep, nutrition and exercise, should be addressed before using a peptide as a "shortcut" to fix health complications, Kahn said.

Bradley agreed, adding that "the same instinct that drives patients toward unnecessary surgery drives them toward complex peptide stacks when the real leverage is upstream and boring."

Kenny Santucci, a fitness expert and founder of Strong New York, shared with Fox News Digital that he takes peptides for muscle building himself – but noted that it’s not right for everyone.

Especially for younger individuals, whose bodies are "already working at optimal levels," peptides may be unnecessary, he said.

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"If you take care of yourself — if you’re eating right, sleeping right, working out — you probably don't need much," he said. 

"I think as you get older, these things start to help out a little bit, or if you suffer from an injury and you want to take something that will help repair the tissue quicker, that's great."