• Testosterone-maxxing is a hot trend in fitness and longevity, but too much can have side effects.
• New research suggests a majority of men are getting testosterone therapy without the right safeguards.
• A urologist explains who can benefit from testosterone and who should avoid it to prevent risks.

America is reaching peak testosterone.

In 2026, interest in the hormone is everywhere, from T-maxxing trends on social media to the US government's MAHA campaign. Testosterone replacement therapy (TRT) use has quadrupled in the past three decades, up to as many as 11 million Americans.

For some of them, the treatment may be doing more harm than good, new research suggests.

A majority of men who are prescribed testosterone don't meet the current guidelines for safe, effective treatment, according to a study from the University of Michigan.

That could worsen the risk of serious side effects, including infertility, heart attack, and stroke, and long-term dependence on TRT, which can dampen the body's natural production of testosterone.

While testosterone is an essential hormone for health, finding the right balance is complex because there's no one-size-fits-all treatment. A urologist explains what to know about the risks and benefits of testosterone, and how hormone trends are changing the landscape of men's health.

Who can benefit from testosterone therapy?

Healthy testosterone levels are crucial for energy, sex drive, muscle, and metabolism.

T-maxxing influencers might promise that it can get you a six-pack and supercharge your focus and performance, but doctors say the benefits are much more modest — if you need a boost at all.

A blood test can check if you have low testosterone and could benefit from TRT. It's typically taken first thing in the morning, and confirmed with a follow-up blood test on a different day.

Low testosterone is anything below 300 nanograms per deciliter for most healthy adult men.

You should also rule out conditions like sleep apnea, which are linked to low testosterone but can worsen with testosterone therapy.

Men who could benefit from testosterone might experience symptoms ranging from brain fog and low energy to reduced libido and erectile dysfunction. It can take anywhere from a few weeks to a few months for TRT to make a difference, depending on the symptoms.

When T backfires

In the latest research, endocrinologists looked at data from 200 men who were prescribed testosterone at the university clinic.

They found that only 12% of the men met the criteria for treating low testosterone, confirmed by two blood tests.

That means the other 88% — 176 men — may have been inappropriately given TRT, including some who had sleep apnea or prostate cancer.

On average, the men studied were in their 50s, but some as young as 18 were also prescribed testosterone.

If they don't need it, young men on testosterone could be putting their long-term health at risk, since taking TRT can make it harder for the body to produce its own supply of the hormone over time.

High testosterone levels can also increase the body's volume of red blood cells, a risk factor for high blood pressure that, in extreme cases, may lead to a heart attack or stroke. It can also impair fertility by temporarily reducing sperm count.

And taking T can potentially exacerbate serious health conditions like prostate cancer, potentially fueling tumor growth, per the Mayo Clinic.

The findings are concerning, given how popular testosterone has become in the wellness industry and the potential for misuse without clear guidelines, said study authors Dr. Maria Papaleontiou and Dr. Sophia Sinha, both professors at the University of Michigan.

"Testosterone has been coined as the 'fountain of youth' to optimize performance through enhancing muscle and improving energy levels in social media," they told Business Insider in a joint email interview. "Testosterone therapy can help some people who truly have low testosterone, but it is not risk-free."

Major update coming soon for testosterone therapy guidelines

Doctors understand that this is not a black-and-white issue.

While testosterone treatment can have side effects, low testosterone is also a health concern, Dr. Justin Dubin, director of men's sexual health at Baptist Health Medical Group, told Business Insider.

Dubin, who was not involved in the study, said prescribing TRT outside the guidelines may not always be harmful. Yes, TRT can be overprescribed to men who don't need it, but it is also underprescribed to men who could benefit, Dubin said.

"Guidelines are guidelines, they're not law," Dubin said. "There are gray areas, and we need to give care in the gray. That's where most doctors live and where most patients live."

The benchmark for healthy testosterone is so nuanced, Dubin said, that the American Urological Association has gathered a panel to discuss a major update to its guidelines on treating testosterone deficiency in the coming year or two.

For now, Dubin said the growing popularity of testosterone is a good thing, as it's prompting a more proactive approach to medical care for men, who are notorious for avoiding the doctor's office until there's an emergency. As long as guys are going about it the right way by speaking to their doctor instead of just buying stuff online, he's all for it.

"I think that's a wonderful thing because this is a gateway to men's health. This is how we can access a lot of guys, get them in to learn about their blood pressure, whether they have diabetes, heart disease," he said. "I'm actually excited and hopeful."

• Serena Williams is returning to tennis at age 44, with her first pro match the week of June 8.
• Williams has been open about using a GLP-1 to lose weight, saying it helps her move better.
• Her comeback is great news for people who believe in peptides for longevity and performance.

The GOAT is bounding out of retirement.

Tennis great Serena Williams is back in the game, after openly endorsing GLP-1s for weight loss, and emphasizing how great her knees feel at her new, lower weight.

"I'm moving better on Ro," she said in a Super Bowl ad for Ro, a telehealth company that prescribes Ozempic, Wegovy, and Zepbound. (Williams' husband, Reddit cofounder Alexis Ohanian, sits on the board and is a major investor.)

In the commercial, Williams said she can move more easily and enjoy steadier blood sugar levels throughout the day while she trains. In general, she feels "healthier" on her injectable medication, which she's said helped her lose 34 pounds after the birth of her second child in 2023.

"After having two kids, I wasn't able to be at a weight that was healthy for me," Williams told the "Today" show when she first announced her paid partnership with Ro in 2025.

Her comeback is huge for tennis, of course — but also for the burgeoning peptide movement.

Yes, GLP-1s ("glucagon-like peptide-1") are peptides.

For the uninitiated, injectable peptides are hot stuff right now. They have become wildly popular among gym-goers, athletes, and bodybuilders looking to trim fat, control inflammation, and avoid injuries. Ultimately, they want to find an edge in their routine.

Peptides are critical signaling molecules our bodies use to build muscle, heal injuries, and control hormones. Gym bros' favorite peptides include BPC-157 (aka "the Wolverine shot") for recovery, ipamorelin CJC-1295 for lean muscle growth — and, of course, GLP-1s for weight loss.

To be clear, Williams isn't suggesting that GLP-1s should be used as performance-enhancing drugs. She is simply emblematic of a growing trend, from regular folks on up to competitive bodybuilders and elite athletes, who are using GLP-1s to stay nimble as they get older.

Her experience mirrors what many doctors are seeing in clinical practice: Their patients are recognizing GLP-1s as a health optimization tool — seeing that the fat reduction and anti-inflammatory benefits of these drugs go beyond treating diabetes and obesity. Research shows the medications can improve heart health, liver function, and sleep quality. And scientists are also probing whether these drugs could help with healthier aging and longevity.

"It's the most powerful drug we've ever seen for helping people lose body fat," exercise physiologist Pat Davidson, who is using an unapproved GLP-1 drug to help shred fat for bodybuilding, told Business Insider. "You are never putting that genie back in the bottle."

GLP-1s target dangerous belly fat

The trend isn't limited to high-powered sports stars.

In San Francisco, Dr. Nima Afshar, a concierge doctor at longevity-focused Private Medical, said he has "dozens" of elite clients who are using these drugs to remove dangerous visceral fat from their midsections and feel better in their bodies.

Visceral fat is stored deep in the belly, providing essential cushioning for vital organs such as the liver and kidneys. While some visceral fat is normal, too much can be a problem, as this fat is metabolically active, and can impact a person's risk of developing chronic conditions like heart disease and diabetes.

Increasingly, Afshar is initiating conversations with patients who he says are "not that overweight" but who he thinks could use these drugs to boost their longevity by driving down visceral fat stores and lowering inflammation across the body.

"I almost don't use the word weight," Afshar said. "Some people can carry visceral fat, but tolerate it well and have no metabolic effects — that's uncommon." For most people, extra "toxic" mid-section fat, which is not always visible, "can ultimately make you not feel quite as good."

Once the negative signaling from that extra visceral fat is gone, a whole chain of health benefits can ensue, he said.

Afshar uses multiple clinical measurements — including InBody scans, routine bloodwork, liver and kidney ultrasounds, and blood pressure readings — to assess whether GLP-1s could be prescribed to improve a patient's health.

At the same time, he recommends all his patients on GLP-1s up their protein intake to "the maximum" recommended dose, and incorporate more movement into their daily routines, to help safeguard their musculature and prioritize fat loss over muscle wasting as they eat less food.

Some private insurers are getting wise to the same idea and mandating that patients adhere to some kind of exercise and nutrition program in order to get access to these medications.

Dr. Mitch Biermann, an obesity medicine physician at Scripps Health in San Diego, said the practice is emblematic of a wider shift in his field, toward a more holistic assessment of excess fat and body composition.

While insurance companies may not cover every indication (i.e., medical reason to take a drug), doctors are increasingly prescribing GLP-1s to a wider array of people with health concerns tied to carrying around excess weight, including joint pain, inflammation, and high blood pressure.

"I think there are quite a lot of indications that people can justifiably use the medicine," Biermann said. "There are just many different definitions of obesity now."

Bodybuilders and athletes are using peptides to get an edge

Whether it was steroids or insulin, bodybuilders have long used exogenous hormones to pursue bulgier muscles, along with protein-rich diets and more strength training than cardio.

GLP-1 drugs are essentially the next generation of that playbook: powerful new drugs that are like supercharged versions of our own hunger-checking hormones, which can help athletes get lean.

Take Davidson, the bodybuilder, who is gearing up for a couple of Mr. Universe-style bodybuilding competitions this July. He's aiming to cut his body fat, without sacrificing muscle.

So, alongside his ultra-high-protein, low-carb diet, he started taking an ultra-powerful but not-yet-released GLP-1 drug called retatrutide, which is still in development at Eli Lilly, about three months ago. (He's part of a groundswell of gym-goers tapping into underground "peptide" markets selling research materials.)

Davidson said he has lost over 30 pounds in three months. He feels like the GLP-1 has helped him maintain more strength than he usually does in the slim-down phase before a big event.

"I really haven't gotten any weaker," Davidson said.

Afshar said the "super optimizers" like Davidson are rarities in his practice, but he knows at least a few people who fit into the category.

Doctors vehemently recommend against doing this without medical supervision.

Williams is not part of this performance enhancement and fitness-optimization-through-peptides band of GLP-1 users; she is promoting these drugs for FDA-approved uses, including blood sugar control and clinical weight loss.

Still, her big comeback to the court next week is great news for the pro-peptide guys, who are keen to show that peptides are much more than drugs to treat chronic diseases like obesity and type 2 diabetes.

• I'm a registered dietitian who relies on Trader Joe's for easy and nutritious meal options.
• Some of my favorite breakfast items include the store's Greek yogurt, bread, and frozen fruit.
• Trader Joe's frozen rice medley and steamed lentils help me make quick and easy meals.

As a registered dietitian, my happy place is wandering the aisles of a grocery store — especially Trader Joe's.

It's been one of my favorite stores since I was a child, and it's still one of the first places I go when I want to pick up items that make nutritious eating feel more realistic.

Here are some of the many items I always add to my cart.

Trader Joe's roasted-garlic hummus is satisfying on its own or when paired with veggies.

Hummus is one of my favorite foods for rounding out snacks and meals.

Since it's made primarily from chickpeas, it adds fiber, plant-based protein, and iron in a form that's easy to eat.

I use the roasted-garlic version as a dip, sandwich spread, salad dressing, or addition to a snack plate, and I especially love pairing it with Trader Joe's mini cucumbers for the perfect no-prep snack.

Plain, nonfat Greek yogurt is one of the most versatile items in my fridge.

The combination of protein and live probiotic cultures makes Trader Joe's Greek yogurt one of my most-used staples.

I use it as a breakfast base with fruit and chia seeds, as a smoothie thickener, or in savory meals as a sour-cream substitute.

I usually buy the plain version with no added sugar, so I can add my own fruit or chia jam, and control the sweetness myself.

Strawberry kefir is easy to drink on my way out the door.

As a fermented dairy product, kefir contains a wider variety of probiotic strains than yogurt and can help support healthy digestion.

The strawberry version from Trader Joe's is drinkable and lightly sweet, without the pronounced tartness plain kefir can have.

On mornings when I don't have time to put breakfast together, I'll pour a glass alongside a piece of seeded toast or fruit for a quick, gut-health-boosting breakfast.

One thing to note: Trader Joe's flavored kefirs contain added sugars, so if you're looking to avoid that, I suggest going for the plain version.

Trader Joe's frozen rice medley is a major time-saver.

I love having Trader Joe's rice medley in my freezer because it provides a more interesting base for dinner.

The mix of whole grains adds more fiber than white rice alone and pairs well with curries, stir-fries, and roasted vegetables. I just microwave it in the pouch for three minutes.

Garbanzo beans provide protein, fiber, and so many options.

Each half-cup serving of Trader Joe's garbanzo beans contains both fiber and plant-based protein, making this a must-have item in my pantry.

There are so many ways to prepare these beans. I air fry them for a crunchy snack, toss them into salads and grain bowls, stir them into soups, add them to dense bean salads, or blend them into sauces.

Since they're shelf-stable, I always have a can (or three) on hand to make a filling meal with minimal prep.

The sesame-crunch salad kit is a low-effort meal that's ready in under 5 minutes.

I love salad kits that taste good because they make me far more likely to prepare lunch instead of defaulting to takeout.

Trader Joe's sesame-crunch chopped salad kit has pre-shredded vegetables, a flavorful sesame dressing, and crunchy toppings that make it feel like a real meal instead of a side salad.

To make it more substantial, I like to add grilled chicken and edamame.

Trader Joe's steamed lentils make it easy to add fiber and protein to my diet.

Lentils are one of my favorite foods for adding plant-based protein and fiber to a meal. I especially like Trader Joe's precooked version because it saves me a lot of time.

I use them in a shortcut for lentil soup, as the base of bowls, and even in tacos when I want a plant-forward meal. They're also a good source of iron, which is another reason they're a staple in my fridge.

Frozen turkey burgers are a lean protein source that can be served with or without a bun.

Trader Joe's turkey burgers are one of the freezer staples I rely on most when I need dinner ready quickly.

Turkey is a complete protein and provides a good source of B vitamins like B6 and B12, which support energy production, mood, and cognitive function.

These burgers cook quickly in the air fryer or on the stove, and I use them in burger bowls, on salads, or with a whole-grain bun and sweet-potato fries for a quick weeknight meal.

The frozen fire-roasted bell peppers and onions make taco night easy.

Bell peppers are a great source of vitamin C, and the fire-roasting process gives them a depth of flavor you wouldn't expect from a frozen vegetable.

I add these to tacos, fajitas, and grain bowls when I want a vegetable that's already chopped, cooked, and ready to eat. This product saves me time, adds color and flavor, and makes it easier to eat my servings of vegetables.

Edamame is a great source of fiber.

Edamame is one of the few plant-based foods that contains all nine essential amino acids — AKA the ones the body can't make on its own and, therefore, has to get from food.

The legume is also an excellent source of fiber, which supports digestion, helps stabilize blood sugar, and sustains fullness.

I keep a bag in the freezer at all times, and like to steam a bowl for a mid-afternoon snack.

Frozen fruit is just as nutritious as fresh, and this berry blend never goes to waste.

Frozen fruit is one of the easiest ways to keep a healthy option on hand without worrying about it going bad.

Plus, since frozen fruit is picked and processed at peak ripeness, its vitamin and antioxidant content is comparable to that of fresh versions.

I especially like picking up Trader Joe's Very Cherry Berry blend, which provides a nice variety of cherries, blueberries, blackberries, and raspberries. It's perfect for smoothies or as an oatmeal topping.

I always grab a loaf of Trader Joe's organic seeded bread.

Trader Joe's organic seeded bread makes toast or a sandwich feel more substantial. The seeds are a great source of healthy fats, magnesium, and fiber.

I especially like using this bread for turkey and avocado sandwiches at lunch, and I'll have it with peanut butter and banana before a workout.

Keep reading our Trader Joe's diaries here.