For over a decade, every testosterone product in the United States carried a black box warning. This is the FDA’s most serious safety label. It stated that testosterone therapy may increase the risk of heart attack and stroke.
That single warning changed how millions of men and women thought about hormone health. Prescribing rates dropped. Conversations shifted from “How do we optimize your health?” to “Is this even safe?”
People who could have benefited from treatment were left untreated. They lived with fatigue, brain fog, low drive, and shrinking muscle mass because no one wanted to risk it.
Some were told to try lifestyle changes alone. Others were put on antidepressants or sleep medications for problems that may have been hormonal all along.
The problem? That warning was built on shaky ground.
The basis for the FDA black box warning cameIt came from a handful of smaller, lower-quality studies published between 2010 and 2014, many of which had serious design flaws. The fear that testosterone therapy might hurt the heart didn’t come from a single, clear-cut study.
One of the most cited was the TOM trial in 2010. It was stopped early after a small number of older men with multiple health problems experienced heart-related events while on testosterone.
The study only included 209 men. Most had severe physical limitations and chronic illnesses. It was never designed to measure heart outcomes.
Another was a 2013 study that looked back at VA medical records and initially reported higher rates of heart attack and stroke among men prescribed testosterone. That study was later corrected after researchers found errors in the data.
Despite these problems, the FDA took action. In 2014, the agency issued a safety warning about heart risk with testosterone products. By 2015, a black box warning was added to all testosterone products, and manufacturers were told to fund a large-scale study to settle the question once and for all.
That study became TRAVERSE.
But by then, the damage was done. Doctors became hesitant to prescribe testosterone even to patients who clearly needed it. Patients who had been doing well on therapy were taken off it.
An entire generation of men and women with low hormone levels were told to wait, based on evidence that would later fall apart.
The TRAVERSE trial is the largest and most rigorous study ever done on testosterone and heart safety. Here’s what made it gold standard:
The result: no meaningful difference between the placebo and testosterone group. About 7.0% of men on testosterone had a major heart event, compared to 7.3% on the placebo. In plain terms, the men taking testosterone fared just as well as the men who weren’t.
The findings were published in the New England Journal of Medicine in 2023, one of the most respected medical journals in the world. The study’s investigators pointed out that TRAVERSE tracked more heart events than every previous testosterone study combined. It is by far the most reliable answer we’ve ever had.
The trial also found no increase in prostate cancer or prostate-related problems.
It did, however, find slightly higher rates of irregular heartbeat (specifically a type called atrial fibrillation), blood clots, and kidney issues in the testosterone group.
These findings are now reflected in updated product labels. They are also exactly the kind of things that proper monitoring catches early.
Based mainly on the TRAVERSE results and additional blood pressure monitoring studies, the FDA updated the labels on all testosterone products on February 28, 2025. The key changes included:
This wasn’t a minor tweak. The FDA was acknowledging that the original heart warning, while understandable given the limited data in 2015, wasn’t backed by strong science.
For patients considering hormone optimization, this means the conversation with your provider no longer needs to start with fear. It can start with the question that actually matters: what are your symptoms, and what do your labs say? That is a better starting point for everyone involved.
If you’ve been holding off on treatment because of heart concerns, this changes the conversation. Here’s what the old warning may have cost you:
The studies that triggered the original warning were small, poorly designed, and later corrected. One enrolled just 209 men. Another had to issue a data correction after publication. Neither was built to measure heart outcomes as a main goal.
The TRAVERSE trial enrolled over 5,200 participants. It followed them for nearly three years. It found no increased heart risk. You were worried about something that the best available science does not support.
Every year spent avoiding testosterone therapy because of an inaccurate warning is a year of living with symptoms that didn’t need to be there. Low energy, brain fog, poor sleep, declining strength.
These aren’t just inconveniences. They affect your work, your relationships, and your quality of life.
Think about what that looks like day to day. You skip the gym because you are too tired. You lose patience with your partner because your mood is off. You cannot focus at work the way you used to. You chalk it up to aging or stress. But the real issue might be something a simple blood test could catch.
The longer these symptoms go unaddressed, the harder they are to reverse. Muscle loss leads to weight gain. Poor sleep leads to worse energy. One problem feeds another. Getting tested early can break that cycle before it takes hold.
The men in the TRAVERSE trial had their levels checked regularly. Doses were adjusted to keep them in a healthy range. They had ongoing follow-up visits and blood work. Under that kind of care, there was no increased heart risk — and many experienced real improvements.
This is exactly the kind of care Castle Rock Hormone Health provides. As Dr. Kelli Weiner explains:
“We’re always checking labs every three months to make sure we’re right where we want to be and also checking in with the patients, making sure they’re still feeling really good.”
The clinic includes all lab work in the cost of the program. Dr. Lee Moorer is direct about why:
“We roll in the cost of laboratory values and medicines. If you need labs more often than every three months, it’s just part of the program. And we eat that cost.”
**This article has been reviewed by qualified medical professionals for accuracy, but it is intended for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or another qualified healthcare provider with any questions about a medical condition or symptoms. Never disregard or delay seeking professional advice based on information read here.