If you’ve been online recently, chances are you’ve heard about “peptides” and how they can supposedly fix, well, anything.
Whether you want bigger muscles, glowing skin or more years added to your lifespan, you can find a peptide designed to help.
The trendy synthetic chemicals come in injections, pills, powders and creams. They’re widely available online, and you can buy them without a prescription.
They’re everywhere on social media, with influencers and biohackers promoting the experimental peptides as a cure-all.
Peptides are not new. In fact, they’re already inside of us, and certain peptides have been used for decades in medicine. But the boom in unapproved, lab-made peptides has many health experts concerned. Here’s what to know before trying them:
What are peptides?
Peptides are short-chain amino acids, which are the “building blocks” of protein, Dr. Jordan Metzl, a sports medicine physician at the Hospital for Special Surgery, tells TODAY.com.
“They’re made throughout our body … and they can also be synthesized,” Metzl explains.
In the body, peptides signal to regulate processes like metabolism, immune function or hormone production. Different peptides target different receptor sites in the body.
“The first isolated peptide was insulin, which is made by the pancreas and works on cells to regulate blood sugar,” says Metzl. Human growth hormone is also a peptide.
“Our body makes thousands of peptides on its own that are involved with a whole host of things,” Dr. Akshay Syal, NBC News medical reporter, told TODAY.
Glucagon-like peptide-1 receptor agonists, aka GLP-1s, are one of the best-known synthetic peptides and the active ingredient in weight-loss drugs like semaglutide. These act on receptors to influence insulin, hunger and gastric emptying, Metzl explains.
Synthetic vasopressin and oxytocin (which is used during labor) are other approved peptides commonly prescribed as medications to patients, says Syal.
“There’s no doubt that peptides are important, but it’s not news. We’ve known about insulin, for example, for 106 years,” Dr. Ezekiel Emanuel, a professor of medical ethics and health policy at the University of Pennsylvania, tells TODAY.com.
What is new is the abundance of unapproved peptides marketed to improve our health in various ways, such as BPC-157 or tb500, without rigorous research to back them up, says Emanuel.
Unlike insulin and GLP-1s, which are among the few peptides approved as drugs by the U.S. Food and Drug Administration, most of the peptides you can buy online are unproven and under-regulated, the experts warn.
Peptides benefits
Since peptides target specific bodily functions, there’s a lot of interest in using them for therapeutic purposes outside of the already approved treatments, Metzl explains.
The problem? The claims about uses and benefits are outpacing the research on safety and effectiveness.
“There’s now a limitless number of peptides being made and a limitless number of claims,” says Metzl.
Some of the most common include anti-aging, increasing muscle mass, enhancing athletic performance and boosting skin health.
There’s an increasing trend of “stacking” peptides, or taking several at a time, to maximize the benefits, Emanuel notes.
However, the scientific evidence is lacking. Most of the data on unapproved peptides comes from laboratory or animal studies.
While peptides may hold promise, the research in humans simply isn’t there yet, Metzl adds.
Until then, the wild west of unapproved peptides is full of unknowns, and potential risks.
Peptides risks
Since most peptides aren’t approved as drugs or dietary supplements by the FDA, they fall into a regulatory gray area, NBC News previously reported. Some are considered “for research use only” or “experimental” chemicals.
“All the peptides that these storefronts are selling, like BPC-157 or tb500, they’re unproven. Some have been supposedly tested in mice and rats,” says Emanuel.
There’s been a boom in peptides sold online by vendors outside the U.S., raising concerns about ingredient safety.
Due to the lack of research in humans, the risks of peptides are largely unknown. But there’s concern that certain peptides may stimulate the growth of cancer cells, the experts note.
“We have no idea about the long-term effects. … We need more rigorous studies,” Emanuel notes.
“We don’t know enough about them yet to be taking them willy-nilly,” Metzl adds.
Lifestyle changes to try before taking peptides
If you’re looking to improve your longevity, promote muscle growth or enhance performance, you don’t need to take peptides, the experts emphasize.
There are plenty of lifestyle changes you can make to reap the benefits popular peptides claim to provide, says Metzl.
Research has shown that daily habits are the foundation of a long, healthy life. But they take some effort.
“We live in a society of quick fixes,” says Emanuel.
Metzl adds: “At the root of the problem is that many people would rather take a pill than do the work.”
Lifestyle changes may not be trendy or exciting, but they are effective — and usually free.
“I think starting with natural methods first makes a lot more sense, especially until we learn more about peptides,” says Metzl, who authored, “Push: Unlock the Science of Fitness Motivation to Embrace Health and Longevity.”
From botanical extracts to powerhouse peptides, the latest skincare ingredients are changing the beauty game. Lifestyle expert Elycia Rubin joins California Live’s Jessica Vilchis to share under-the-radar beauty boosters that deserve a place in your everyday routine.
Eat protein-rich breakfasts
When it comes to longevity, the goal isn’t to live as long as possible, according to Emanuel, who authored “Eat Your Ice Cream: Six Simple Rules for a Long and Healthy Life.”
The aim is to keep living in good health with as few diseases and problems as possible, or maximize your “healthspan.”
If you want to support healthy aging, start with breakfast. “It’s such a simple thing,” says Emanuel.
Eating a high-protein breakfast supports muscle growth, blood sugar control and keeps you feeling full, which can help with weight loss, TODAY.com reported previously.
Try to prioritize whole foods and avoid refined carbohydrates and sugary cereals, says Emanuel.
Eggs, greek yogurt and cottage cheese are nutritous, high-protein options. Emanuel’s go-to breakfasts include omelets and yogurt bowls topped with fruit and hemp hearts or nuts.
If you’re vegan, try a tofu scramble or beans at breakfast.
But you don’t need to overdo it with the protein, says Metzl. Aim for about 20–40 grams of protein at each meal.
Increase your fiber intake
Fiber is one of the most important nutrients to prioritize for healthy aging, Emanuel previously told TODAY.com.
Fiber is best known for supporting digestive health and preventing constipation, which can lower the risk of colon cancer. It also protects heart health, aids with blood sugar control and supports weight management.
The recommended intake for adults is 25-38 grams of fiber per day — about 95% of Americans fall short of that.
You can increase your fiber intake by eating more plant-based foods, like fruits, vegetables, legumes and whole grains.
Berries and kiwis are some of Emanuel’s favorite high-fiber fruits.
Fiber-filled veggies include broccoli, cauliflower, and Brussels sprouts. All legumes pack a fiber punch, but white beans, lentils, and black beans are particularly rich in this gut-healthy nutrient.
Move daily
“Activity, activity, activity,” says Metzl.
People often get caught up in the number of minutes to exercise or calories to burn, but the most important thing is that you move every day.
“We have the most evidence for daily exercise,” Metzl notes. If you don’t have time for a workout, simply pushing yourself while doing your normal activities can make a big difference.
Just two minutes a day of vigorous physical activity, independent of exercise, can be valuable for extending longevity, Metzl says. Anything that gets you huffing or puffing — taking the stairs, carrying laundry, or running to a train — counts.
Emanuel prioritizes daily bike rides and walking, and cautions against extreme workouts.
If you’re looking to increase muscle growth, consistent strength training is crucial, but multi-joint compound exercises and progressive overload may help you get faster results.
“It’s a lot safer than (injecting) peptides,” says Metzl.
Keep a consistent sleep schedule
Most adults should aim to get seven to nine hours of sleep every night, but maintaining a consistent sleep schedule may be just as important as the duration.
Sleep consistency is crucial for good health and longevity, says Metzl. This means going to bed and waking up around the same time every day, which can help regulate our circadian rhythm.
“Everyone talks about it, but it’s difficult to do,” says Metzl.
If you don’t already, try sticking to a regular bedtime and a consistent morning alarm — on weekdays and weekends.
Not getting enough consistent, high-quality sleep can cause drowsiness and irritability the next day. Over time, sleep deprivation can increase the risk of chronic diseases, mood disorders and cognitive decline, TODAY.com reported previously.
Have fun with others
After reading this article, get off your computer or phone and hang out with your friends, family or neighbors. Seriously.
“Especially for longevity, one of the most important things is community,” says Metzl.
“If someone asked me to recommend one thing to boost wellness, I’d say throw a dinner party,” Emanuel adds. A dinner party fosters social connectedness, facilitates engaging conversation, and improves mood — plus, you can enjoy a home-cooked meal.
Not only does spending time with others make us feel happy and fulfilled, Emanuel notes, but it also decreases cortisol, the stress hormone, and may improve our biological health.
“Social interaction is essential to human beings, we’re social animals and we’ve got this big brain for a reason,” says Emanuel.
Stay up-to-date on routine vaccines
Vaccination prevents severe illness and death from infectious diseases. There’s growing body of evidence that routine vaccines given in adulthood also protect against dementia.
If you’re looking to protect your body and brain as you get older, staying up to date on vaccines is crucial, Emanuel explains.
“Especially for people over 50, four vaccines can reduce your risk of cognitive decline and dementia,” says Emanuel.
These include the shingles vaccine, pneumococcal vaccine, DPT vaccine (diptheria, tetanus and pertussis) and the flu shot.
The shingles vaccine, which Emanuel says is “substantially underutilized,” is over 90% effective at preventing shingles and its complications. In a 2025 study of over 430,000 adults, those who received the shingles vaccine had a 18% lower risk of being diagnosed with dementia in the following two years.
The pneumococcal vaccine, which protects against infection from the bacteria that causes pneumonia, is associated with a lower risk of Alzheimer’s in adults over 65, research shows.
The DPT vaccine, aka Tdap, is recommended for adults every 10 years. In a 2025 meta-analysis of data from over 1.4 million adults, Tdap vaccination was associated with a 33% lower risk of all dementias.
“The influenza vaccine is the most recent one shown to decrease cognitive decline,” says Emanuel. A 2026 study in Neurology shows that the high-dose flu shot is associated with a 55% lower risk of Alzheimer’s in adults over 65.
“Cognitive decline is a serious worry, so this is one thing you can and should do,” says Emanuel.
When it comes to unapproved peptides, “buyer beware,” both experts emphasize.
This story first appeared on TODAY.com. More from TODAY:
