The Peptide Craze: What Your Doctor Wants You to Know

The staggering gap between hype and evidence

A patient came to my office last month carrying a hot pink refrigerator bag (the kind you get at Trader Joe’s). When she pulled out a handful of syringes, I assumed they contained compounded GLP-1s (e.g., Ozempic or Zepbound). But no! They were full of something called a “Wolverine stack,” a combination of peptides she’d ordered online. These peptides promised to heal her torn rotator cuff faster than physical therapy ever could. She’d spent OODLES of money on a three-month supply and was injecting herself daily based on a protocol she found online.

“My trainer swears by it,” she told me. “Everyone is using them!”

She’s not wrong about that. The peptide economy is booming. Peptides have become the wellness industry’s latest obsession, pushed by influencers and biohackers, embraced by Hollywood and Silicon Valley, and increasingly finding their way into the medicine cabinets (or refrigerator bags) of people searching for healing and an edge against aging.

But here’s what you need to know: most of these substances operate in a regulatory gray zone, with limited human evidence and significant safety concerns. Once again, most mortals find themselves caught between a medical system that can’t give them adequate time or attention, and a wellness industry selling hope without accountability.

What Are Peptides, Actually?

Let’s start with the basics. Peptides are short chains of amino acids, the building blocks of proteins. Think of them as text messages to your body, telling cells what to do: “Heal that damaged tendon!” or “Build more muscle!” or “Reduce inflammation in the gut!”

Your body already makes thousands of peptides naturally. Insulin, for instance, is a peptide made by the human pancreas. It’s also an injectable peptide that has been used safely for over a century to treat type 1 diabetes. Did you know your body makes its very own GLP-1 peptide? As you know, synthetic GLP-1 peptides like Ozempic and Wegovy have transformed diabetes and obesity treatment through rigorous clinical trials and FDA approval.

These FDA-approved peptides are medications with robust safety data and proven efficacy. They went through years of testing, involving thousands of patients, before reaching your doctor’s pharmacopeia.

But when celebrities and wellness influencers talk about “peptide therapy” they’re usually referring to experimental substances that have not been approved for human use, sold online as “research chemicals” with disclaimers stating they’re “not for human consumption.” The irony, of course, is that these same websites provide detailed instructions on exactly how humans should consume them.

The Peptides Everyone’s Talking About

Walk into any longevity clinic or scroll through a “biohacker”’s website, and you’ll encounter a few names repeatedly:

BPC-157 is perhaps the most popular, nicknamed part of the “Wolverine stack” for its supposed healing powers. Derived from a protein in human gastric juice, it’s promoted for everything from tendon injuries to gut healing to brain protection. The evidence? Thirty-six studies, mostly in rats, largely from a single research group in Croatia. In humans? Three small studies—the largest involving just sixteen people—with no control groups, no blinding, and often conducted by clinics that sell the peptide.

TB-500 (Thymosin Beta-4) is another favorite, marketed for wound healing and tissue regeneration. This one has slightly better evidence. Some clinical trials in humans for pressure ulcers and dry eye showed promise. But TB-500 is actually just a fragment of the full thymosin beta-4 protein, and the research doesn’t clearly establish whether the fragment works the same way as the complete molecule.

Both are banned by the World Anti-Doping Agency. Neither are FDA-approved. Both are being injected daily by people who’ve been convinced they’re the solution to injuries that traditional medicine has failed to heal.

Why the Peptide Boom Is Happening Now

First, the massive success of GLP-1 medications proved that peptides could be transformative. If semaglutide (the active ingredient in Ozempic) could help people lose significant weight, what else might peptides do?

Second, trust in traditional healthcare is at an all-time low. Patients are frustrated by fifteen-minute appointments, doctors who don’t listen, and a system that treats symptoms without addressing root causes. When your doctor doesn’t have time to help you, a wellness clinic promising anti-aging treatments and personalized “optimization” sounds pretty appealing, right?

Third, social media amplifies the messaging about peptides. Podcasters like Joe Rogan and Andrew Huberman have discussed peptide stacks with millions of listeners. Influencers share before-and-after photos. Celebrities whisper about their peptide protocols. And in October 2024, Robert F. Kennedy Jr. (now our HHS Secretary) tweeted that the “FDA’s war on public health” included “aggressive suppression” of peptides, effectively moving these substances from clearly illegal to murky gray area overnight.

Ta-da! Suddenly, peptides went mainstream.

What the Science Actually Shows

The short story is this: the gap between the hype and the evidence is staggering. Most peptide research exists only in animal models. Rats with torn tendons or mice with heart attacks. (I can’t stop picturing a sad rodent on crutches—🤕🐁!!) These studies show interesting things such as faster healing, reduced inflammation, improved blood vessel growth. But animal studies fail to translate to humans more often than they succeed.

In short, you are not a 200-gram rodent!

The human data that does exist is sparse and concerning in its limitations. Many studies lack control groups, meaning we can’t distinguish peptide effects from placebo effects or natural healing. Sample sizes are tiny. We’re talking twelve people in some! Some early trials from the 1990s claimed peptides were “free of side effects” but were never published in peer-reviewed journals, only mentioned in abstracts by the peptides’ original proponents.

We have no long-term safety data. None! We don’t know what happens when someone uses these peptides for months or years. We don’t know if they increase cancer risk, which is a real concern since many peptides promote blood vessel growth, which could theoretically feed tumors. We don’t know about effects on fertility, immune function, or organ systems.

To me, the most worrisome part is that we can’t even be sure what’s in the vials people are buying online. The supplement and peptide industry is largely unregulated. Between 2007 and 2016, the FDA found nearly a thousand products marketed as “dietary supplements” that actually contained active pharmaceutical compounds from prescription drugs. About one-third of sports performance supplements contained steroids or stimulants not listed on their labels.

Some peptides sold online are contaminated with heavy metals. Others contain ingredients that aren’t disclosed. Still others are mislabeled with incorrect dosing information. You’re essentially trusting your health to an industry with no oversight and every incentive to keep selling. (You can read my thoughts on the pitfalls of the wellness industry here.)

What I Tell My Patients

When someone comes to me asking about peptides, I first explain that I fully understand the appeal. I understand the desperation people feel when traditional medicine has failed them. I really do.

But here’s my framework for thinking about this:

First, I distinguish between FDA-approved peptides and everything else. Insulin, GLP-1 medications, and a handful of others have been rigorously tested and proven safe and effective. If you have diabetes or obesity, these are legitimate medical treatments with established benefits that outweigh risks. We should absolutely use them.

Second, I’m honest about what we don’t know. For peptides like BPC-157 and TB-500, we simply don’t have the data to say they’re safe or effective in humans. That doesn’t mean they don’t work, it just means we don’t know. The absence of evidence is not evidence of absence, but know that using under-studied peptides means you’re essentially experimenting on yourself.

Third (and this is crucial), I explore why you’re considering this. Often, the impulse to try peptides (or other wellness hack) stems from a legitimate medical need that isn’t being met. You have chronic pain that physical therapy hasn’t resolved. You have inflammation that standard treatments haven’t controlled. You’re exhausted and no one has figured out why. These are real problems that deserve real solutions, but unregulated peptides are probably not the answer.

Instead, let’s figure out what you actually need. Do you need a different physical therapist? A rheumatologist? A deeper investigation into your fatigue?

Sometimes the path forward isn’t a shortcut; it’s finally getting the comprehensive care you should have had all along.

Fourth, I talk about trade-offs and risk tolerance. Some patients, after hearing all this, still want to try peptides. They know that evidence can lag behind clinical utility. Take, for example, testosterone therapy for women, which is still not FDA-approved for women in the US but offers clear benefits and very little harm when prescribed appropriately. Patients appropriately will say, “I understand the risks. I’ve tried everything else. I’m willing to experiment.” I can’t stop them—nor should I!

So I help them think through the decision more carefully:

• Are you getting the peptides from the most reputable source available?

• Are you aware that if something goes wrong, you may have limited legal recourse?

• Are you prepared if it doesn’t work and you’ve spent a bunch of money?

• Most important: Are you being honest with yourself about why you’re doing this?

The Upshot

I’m not anti-peptide. I’m pro-reality.

I’m believe in hope. I just don’t believe in monetizing magical thinking.

I’ll never tell you that health is achievable through discipline alone. I’ll never promise you perfect health if you spend enough money, follow a specific protocol, or “optimize” sufficiently.

So yes, some peptides will undoubtedly prove valuable as we learn more about them. The research shows promising candidates to help with wound healing, neurodegenerative diseases, and metabolic conditions. I hope some of these substances eventually make it through rigorous clinical trials and become legitimate treatment options.

But we’re not there yet.

In the meantime, I’m here to help you navigate the jungle out there, acknowledging what we don’t know and helping you make decisions that align with your goals and risk tolerance. I’m only one voice, but together we make a fine chorus! 🎵

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🙋🏻‍♀️ QUESTION: Are you considering peptide therapy or have questions about navigating wellness trends? Drop me a comment—I read them all!

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