What doctors want patients to know about injectable peptides

AMA News Wire

What doctors want patients to know about injectable peptides

Apr 29, 2026

Interest in injectable peptides is rising as more people see them promoted online through health and wellness influencers for weight loss, muscle growth, recovery and anti-aging. But behind the buzz is a more important question: Are these products safe, effective and backed by evidence? 

Physicians say patients should look past social media claims and marketing promises and start with a conversation with a doctor because some injectable peptides are not regulated and may carry real health risks.

The AMA’s What Doctors Want Patients to Know™ series gives physicians a platform to share what they want patients to understand about today’s health care headlines.

For this installment, Anthony C. Tam, MD, a family and sports medicine physician with Henry Ford Health, took time to discuss what patients should know about injectable peptides. He is also a team physician for USA Wrestling, USA Cycling and USA Volleyball, and head physician for Michigan Special Olympics.

Henry Ford Health is part of the AMA Health System Member Program, which provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.

Injectable peptides have been around for a while 

“Social media has really focused on this recently, but we've had injectable peptides for a while. One of the most common and heavily used is actually insulin,” said Dr. Tam. "We use insulin injections to help people with diabetes control their blood sugar."

"In the last couple of years, the more notable peptide injections that we have been prescribing are GLP-1 medications, which are better known by brand names like Ozempic or Wegovy," he said. These medications help treat diabetes by controlling “sugars but also serves … to help with weight loss as well" by slowing digestion and making patients feel fuller.

Peptides are now being marketed for wellness

More recently, Dr. Tam noted there has been an influx of people "looking for that edge to improve their health and well-being."

"We're now seeing a wave of other peptide injections that are being marketed by wellness centers and social media influencers," he said. "Unfortunately, many of these products have not been thoroughly tested or reviewed by the Food and Drug Administration, so we don't have data from trials. A lot of these newer peptide injections are promoting anti-aging and improved healing and recovery."

People are using injectable peptides for various reasons

"With these newer injections, the claim that's been studied the most relates to recovery. There was one human trial study involving about 10 to 12 people for knee pain recovery," Dr. Tam said. "The details were limited, but the results suggested there may be some promise in improving overall pain scores."

These newer peptides have some studies, but most are in animal models, not humans, to determine how it would act in the human body. 

“When looking at animal trials and other studies, the results were more promising for overall recovery and anti-aging effects, but there's nothing substantial to show these results would translate to humans," he explained. "And there's minimal evidence on the side effects or consequences of long-term or frequent dosing."

"It's great to see that we're on this route of health, wellness and recovery, but we need more evidence and research before we can make a true recommendation," he said.

There's a big trend in the younger population

When it comes to who is using newer injectable peptides, "it's a lot of different people," said Dr. Tam, noting a growing trend among younger generations, including high school and college-age students involved in "looksmaxxing," which is an online community that primarily targets young men who want to improve their appearance.

"There are also weekend warriors and normal, middle-aged people who are looking for an extra edge to try to improve their health," he said. "Elite athletes also bring up peptide injections, but at that level of competition, we conduct drug testing, and these types of substances aren't allowed."

While interest in new peptide injections continues to grow, Dr. Tam emphasized that "unfortunately, there just isn't enough valuable, statistically significant evidence that points us to be able to recommend them safely."

Newer injectable peptides are not FDA approved

"Insulin and GLP-1s are designed for specific disease, so we know who's a good candidate for them," Dr. Tam said. "With these newer peptides, we don't have the same level of evidence yet. We're not sure about dosing and frequency. What we do know mostly comes from anecdotal reports of side effects."

He added that when research is not standardized, regulated or reviewed by the FDA, there's no guarantee they're being manufactured safely or that the ingredients are what is advertised. On the other hand, he noted, "insulin and GLP-1s are very well studied."

"The interesting thing about GLP-1s is that even with all the research we already have, we're continuing to find even more benefits" and risks related to GLP-1s, Dr. Tam said, "which may be why there's so much interest in these newer peptides. They hint at promising possibilities."

There are not clear guidelines for all peptides

With newer peptide injections, it can be difficult to know who is or isn't a good candidate, while with GLP‑1 medications like semaglutide or Ozempic and Wegovy, doctors have well-established guidelines, said Dr. Tam.

Certain patients—such as those with specific types of endocrine cancers—should avoid GLP‑1s, he explained, and there are clear guidelines for who may benefit most, including people with diabetes, obesity or other chronic conditions that contribute to long-term weight gain.

"It's always best to consult with a physician who can give you the best information and help you make the wisest decision," Dr. Tam advised. "We want to find ways to improve your health in the safest ways possible."

For some peptides, side effects are unknown

With insulin, one of the main side effects is low blood sugar while with GLP‑1s, there's a risk of gastrointestinal issues.

"Sometimes people feel nauseous or experience an upset stomach, diarrhea or constipation," Dr. Tam explained. "There's also a risk of possible pancreatitis with the injections. That's why it's really important to talk with your physician and understand the possible side effects."

He added that newer peptide injections also have side effects that we are still learning about.

"From the research we do have, because they're injections, you can see skin irritation at the injection site," Dr. Tam said. "Fatigue, headaches and GI issues have also been reported. Those seem to be the more common side effects so far, but there's still a lot we don't know" about potential risk to patients.

Newer injectable peptides sold through the "grey market"

FDA approval for peptides, such as insulin and GLP‑1s, ensures oversight of how these medications are manufactured and distributed. But newer peptides that are not FDA‑approved carry additional risks related to possible contamination, safety, sourcing and dosing, according to Dr. Tam, particularly in the grey market where products are manufactured without FDA oversight.

He noted that some of these newer injectable peptides are being sold at wellness spas, online sites and through the grey market for unapproved GLP‑1s, which raises additional safety concerns.

"It's important to know exactly where your peptides come from and how they're manufactured," Dr. Tam said. "Talking it through with your physician can help you make a safer, more informed decision."

It’s important to consult your doctor first

With all substances, “if you don't have all the information about what could or couldn't happen when you take a medication, you might be caught off guard by a reaction or side effects," Dr. Tam said. "You may not know whether something is totally unexpected or actually something we'd anticipate based on the treatment."

"It is similar to blood pressure or diabetes medicines,” he said. “You should always review the possible side effects because if something unusual happens, you know whether that was expected or you need emergency care."

"With the established medications, we have plenty of resources that guide us on proper dosing and how to adjust things if you're having side effects or other issues,” said Dr. Tam. “We don't know much about the newer ones yet." 

That's why it's vital to talk with your physician, he said, adding "more communication is always better."

"All questions are good questions, and I'll always provide the best information and answers I can," Dr. Tam said.