TRT Heart Health: What the Research Actually Shows

Disclosure: This page may contain affiliate or commercial relationships. | Last Updated: August 2026

MEDICAL DISCLAIMER This content is for informational purposes only and does not constitute medical advice. Consult a licensed physician before starting any hormone therapy or treatment.

Few health questions stall a decision faster than this one: could treating low testosterone put strain on the heart? For more than ten years that concern was printed directly on every testosterone product label sold in the United States, and it kept plenty of men from ever raising the subject with a provider. 

TRT heart health worries remain one of the most common reasons men postpone treatment, and for much of that period the evidence behind the warning was genuinely unsettled. Men researching how to increase testosterone deserve a clear read on what the studies actually found, not a headline recycled from a decade-old alert.

This guide walks through where the concern originated, what the largest trial to date measured, what regulators changed and what they deliberately left in place, and which variables genuinely shift the risk picture for an individual. It closes with the questions worth bringing to an appointment before starting therapy.

The Short Answer on TRT Heart Health

For men with a confirmed diagnosis of low testosterone who are treated and monitored by a licensed provider, current evidence does not show an increase in major cardiac events such as heart attack, stroke, or cardiovascular death. That finding comes from the TRAVERSE trial, the largest randomized study of its kind, and it led the FDA to remove boxed warning language about cardiovascular risk from all testosterone products in early 2025.

None of that amounts to a clean bill of health. The same trial reported higher rates of several specific events in the treatment group, and the agency added a new class-wide warning about increased blood pressure at the very moment it removed the older language. Asking is TRT bad for your heart produces meaningfully different answers depending on baseline cardiovascular status, how closely therapy is monitored, and whether the product came from a licensed prescriber at all.

Where Concerns About Testosterone and Heart Disease Came From

The link between testosterone and heart disease entered mainstream awareness in January 2014, when the FDA issued a safety communication about reported cases of stroke, heart attack, and death among men using approved testosterone products.

Later that year the agency convened a joint advisory committee meeting, which produced a recommendation for an industry-wide clinical trial to assess safety in men with age-related hormone decline. A further communication in 2015 required labeling changes and urged caution when these products were used for low testosterone attributed to aging alone.

The worry did not come from nowhere. Observational studies and smaller trials had produced genuinely conflicting signals. One trial in older men with limited mobility was halted early after more cardiovascular events occurred among those receiving treatment. 

Other research pointed the opposite direction, suggesting possible benefit in men with metabolic syndrome or type 2 diabetes. Reviewers looking at the same literature reached opposite conclusions, which is usually a sign that the study designs, not the hormone, were driving the disagreement.

What the TRAVERSE Trial Found

TRAVERSE, short for Testosterone Replacement Therapy for Assessment of Long-term Vascular Events and Efficacy Response in Hypogonadal Men, was the study the FDA had asked for. It was a randomized, double-blind, placebo-controlled trial that enrolled more than 5,200 men between the ages of 45 and 80 across hundreds of sites in the United States. Results were published in the New England Journal of Medicine in 2023.

The design matters as much as the result. Every participant reported at least one symptom of low testosterone and had two separate morning blood draws confirming a low reading. Every participant either had established cardiovascular disease or carried multiple risk factors for it. Men with severe or congenital hormone deficiency were excluded. Participants received either a daily transdermal testosterone gel or a matching placebo gel, with follow-up averaging roughly 33 months.

The primary finding

The trial’s main safety endpoint was the first occurrence of a major adverse cardiac event, defined as cardiovascular death, non-fatal heart attack, or non-fatal stroke. Such an event occurred in 7.0 percent of the testosterone group and 7.3 percent of the placebo group. Treatment met the prespecified statistical criteria for noninferiority to placebo, meaning the researchers could rule out the degree of added harm the trial was designed to detect.

For a population deliberately selected for elevated cardiac risk, that carries weight. Investigators had spent years unable to answer this question with anything better than observational data, and this trial addressed it directly in the group most likely to reveal harm if harm existed. Subsequent position statements from professional bodies, including a European expert panel and the Androgen Society, have described the accumulated randomized evidence as consistent on this point.

The findings that were not expected

The investigators also reported several adverse events at higher rates among men receiving treatment. Atrial fibrillation, an irregular heart rhythm, occurred in 3.5 percent of the testosterone group compared with 2.4 percent of the placebo group. Acute kidney injury occurred in 2.3 percent versus 1.5 percent. Pulmonary embolism, a blood clot lodged in the lungs, occurred in 0.9 percent versus 0.5 percent. Non-fatal arrhythmias requiring intervention were also more common in the treatment group.

The study authors described these results as unexpected and noted that they support existing guidance to use testosterone cautiously in men with a history of blood clots. Several commentators have suggested that similar caution may reasonably extend to men with a history of arrhythmia. A modest increase in fractures also drew discussion after publication, with some researchers speculating that men who feel better early in treatment may simply become more physically active. That explanation remains a hypothesis rather than a demonstrated cause.

What the trial could not settle

Average treatment duration in the trial was under two years, and total follow-up averaged just under three. Hormone therapy is frequently continued for far longer than that. Whether the safety profile holds across ten or twenty years has not been tested and should not be assumed from a study of this length.

The trial also examined one delivery route, a daily topical gel, in a population with mild to moderate deficiency whose levels were checked and adjusted throughout. The lead investigators were explicit that the results should not be read as justification for prescribing testosterone broadly to aging men without a confirmed diagnosis, and they raised the open question of how often that degree of monitoring actually occurs in routine practice. Any honest discussion of TRT heart health has to carry those caveats alongside the headline result.

Before comparing programs or price points, it helps to understand what a monitored testosterone protocol actually involves from testing through follow-up. Read The Complete Guide to TRT in 2026 for a full walkthrough.

The 2025 FDA Label Change and What It Actually Means

On February 28, 2025, the FDA notified manufacturers of class-wide labeling changes for all testosterone products. Three separate things happened at once, and news coverage at the time frequently reported only the first of them.

Led by the trial results, the agency recommended adding the TRAVERSE findings to every testosterone product label, retaining the existing Limitation of Use language regarding age-related hormone decline, and removing boxed warning language related to an increased risk of adverse cardiovascular outcomes across the entire product class.

Led by a separate set of required postmarket ambulatory blood pressure monitoring studies, the agency also required labels to carry product-specific information about increased blood pressure, and required a new blood pressure warning for products that did not already have one. Those studies confirmed an increase in blood pressure with testosterone use class-wide, across every route of administration.

The complete picture is therefore narrower than the headline suggested. Regulators concluded that the evidence no longer supported a boxed warning about heart attacks and strokes, added a warning about a different cardiovascular parameter in the same action, and left in place the caution that these products are approved for men with low testosterone tied to an associated medical condition rather than for aging by itself. 

Anyone weighing testosterone and heart disease questions should read the change as a recalibration rather than an all-clear.

Is TRT Bad for Your Heart? The Factors That Still Warrant Attention

Removing a boxed warning narrows the question rather than closing it. Several specific areas continue to justify monitoring, and they are the areas a thorough provider will want to track from the outset.

Blood pressure

The blood pressure warning is the newest element and the easiest to overlook, partly because it arrived in the same announcement that removed a scarier one. It applies across formulations, not to a single product. Elevated blood pressure is a well-established contributor to long-term cardiovascular risk, so a sustained increase deserves attention even in men whose short-term event risk appears unchanged. Regular readings, both at home and in the clinic, are a reasonable expectation for anyone on therapy.

Red blood cell concentration

Testosterone stimulates red blood cell production. In some men that raises hematocrit, the share of blood volume made up of red cells, to a degree that thickens the blood. Professional guidelines recommend measuring hemoglobin and hematocrit before starting therapy, rechecking during the first months and periodically thereafter, and counseling men about this risk in advance.

Retrospective research has found that men on testosterone who develop elevated hematocrit show higher rates of cardiac and clotting events than men on testosterone whose counts stay within range. That distinction is genuinely useful. It suggests a meaningful share of the risk concentrates in men whose blood counts drift upward unnoticed, which is exactly the scenario routine labs are designed to catch. When hematocrit climbs past the threshold a provider is watching for, the usual options include adjusting the plan, changing formulation, or pausing treatment while levels normalize.

Clotting and rhythm signals

Given the trial findings on pulmonary embolism and atrial fibrillation, men with a personal or family history of blood clots, a known clotting disorder, or a prior arrhythmia have a concrete reason to raise this before starting. Professional guidance has long advised caution in men with previous thromboembolic events, and the randomized data reinforce rather than retire that advice.

Timing after a cardiac event

Endocrine Society guidance recommends against starting testosterone therapy in men who have had a heart attack or stroke within the previous six months, or who have uncontrolled heart failure. Clinicians who treat this population routinely describe holding off during that window as standard practice. TRAVERSE does not change that recommendation, because men in the immediate aftermath of a cardiac event were not the population studied.

Key Variables That Change the Answer for You

General findings describe populations, not individuals. Several factors determine how closely the research applies to any particular man.

Whether the diagnosis is real

The trial studied men with symptoms plus two confirmed low morning readings. Its reassurance does not automatically extend to men taking testosterone without documented deficiency. Published estimates have suggested that a substantial share of men prescribed testosterone never had levels tested beforehand, and that a meaningful proportion do not meet diagnostic criteria at all. A trial result cannot cover a population it never enrolled.

How closely therapy is monitored

Trial participants had hormone levels checked and their regimen adjusted accordingly throughout the study. A program that ships medication without periodic bloodwork is not delivering the intervention that was tested. Men comparing cheapest online TRT clinics should look closely at which labs and follow-up visits are actually included rather than at the advertised monthly figure alone. Our TRT cost guide covers what ongoing monitoring typically adds to the real total, and comparing that line item across services is often more revealing than comparing headline pricing.

Where the product came from

Androgens obtained outside the medical system occupy a different risk category entirely. Over-the-counter testosterone boosters have not demonstrated meaningful effect on hormone levels, and illicit androgens used at levels well above the physiological range carry documented cardiovascular harm. None of the reassurance drawn from randomized data applies to unregulated products used without supervision, and clinicians who treat men in this space consistently identify it as the more pressing danger.

Underlying cardiovascular status

A man with well-controlled blood pressure, no clotting history, and normal kidney function occupies a very different position than a man with poorly controlled hypertension and a prior pulmonary embolism. Both may be candidates, but the monitoring plan, the conversation, and the threshold for stopping should not look the same. This is the single largest reason a blanket answer to TRT heart health questions tends to mislead.

Other treatable contributors

Obstructive sleep apnea, excess weight, heavy alcohol use, and poorly controlled diabetes all suppress testosterone while independently damaging cardiovascular health. Addressing them sometimes improves both hormone levels and cardiac risk without hormone therapy at all. Ruling out reversible contributors before committing to long-term treatment is a reasonable sequence, and a thorough provider will raise it unprompted.

Expectations about benefit

Safety and effectiveness are separate questions, and conflating them leads to poor decisions. For a fuller look at which symptom outcomes the evidence supports and which remain uncertain, see our guide on does TRT work. For help comparing provider models, included services, and monitoring standards across the market, our Best TRT Roundup walks through what different programs actually deliver.

Frequently Asked Questions About TRT Heart Health

Does TRT cause heart attacks?

The largest randomized trial to date did not find an increased rate of heart attack, stroke, or cardiovascular death among men with confirmed low testosterone and elevated cardiac risk who received treatment compared with placebo. That result led regulators to remove boxed warning language on this point in 2025. It applies to men who meet diagnostic criteria and receive monitored care, and it does not extend to unsupervised or non-prescribed use.

Can men with existing heart disease consider testosterone therapy?

Many participants in the TRAVERSE trial had established cardiovascular disease, which is what makes the findings relevant to this group. That said, existing guidance advises against starting therapy within six months of a heart attack or stroke and in men with uncontrolled heart failure. The decision belongs with a provider who has reviewed the full history, and the discussion of testosterone and heart disease should be individual rather than categorical.

Does testosterone therapy raise blood pressure?

Required postmarket studies confirmed an increase in blood pressure across all testosterone products, regardless of how they are administered, and the FDA added a class-wide warning to reflect that in 2025. Men with existing hypertension may want to discuss how their readings will be tracked and what threshold would prompt a change in plan.

How often should heart-related labs be rechecked?

Professional guidance generally calls for a baseline before starting, a recheck within the first several months, and periodic monitoring thereafter, with hematocrit and blood pressure among the standard markers. Exact intervals vary by provider and by individual risk, so it is fair to ask for the specific schedule in writing before committing to a program.

Does low testosterone itself affect heart health?

Observational research has consistently linked lower testosterone concentrations with higher rates of cardiovascular disease and higher all-cause mortality in men. Whether low levels drive that risk or reflect underlying illness has not been resolved, since the conditions that lower testosterone also independently damage cardiovascular health. The association is real, but it should not be read as proof of causation in either direction.

Are over-the-counter testosterone boosters a safer option?

Non-prescription boosters have not demonstrated meaningful effect on hormone levels, so avoiding a prescription in favor of a supplement generally trades a monitored intervention for an unmonitored one with little evidence behind it. Illicit androgens obtained outside medical channels are a separate and considerably more serious concern from a cardiovascular standpoint.

So, is TRT bad for your heart or not?

Based on the strongest available evidence, testosterone therapy in properly diagnosed and monitored men does not appear to raise the risk of major cardiac events. It may raise blood pressure, it may raise hematocrit in some men, and signals around clotting and rhythm disturbances warrant ongoing attention. The realistic framing is that risk is now better characterized and more manageable, not that it has been eliminated.

The Bottom Line on TRT Heart Health

A decade of uncertainty produced a warning that shaped how cautiously testosterone was prescribed and how nervously men approached it. A large randomized trial and a regulatory review have since narrowed that uncertainty considerably. For men with a confirmed diagnosis who receive monitored care, the evidence does not support the fear that treatment raises the risk of heart attack or stroke.

What remains is a shorter and more practical list: track blood pressure, watch hematocrit, disclose any history of clots or arrhythmia, respect the waiting period after a cardiac event, and make sure a real diagnosis precedes a prescription. Those are manageable requirements when a program is built around them, and they are exactly what gets skipped when it is not.

For men who want a structured starting point, PrescribedRX is one option worth considering. Its programs pair lab testing with licensed provider review and ongoing follow-up, which is the model the research was built on. Whatever route a man chooses, the sensible first move is finding out where his numbers actually stand rather than deciding based on a warning that regulators have since revised.

Ready to Get Answers? Book a TRT consultation with a licensed PrescribedRX provider. Review your labs, discuss your cardiovascular history, and decide on your own timeline with a clear picture of the evidence. Contact PrescribedRX

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About This Guide

This article was written and reviewed in accordance with our editorial standards. Clinical information is drawn from peer-reviewed literature, U.S. Food and Drug Administration communications, and professional society guidance available as of August 2026. Regulatory status and clinical guidance may change over time. Content is reviewed by a licensed healthcare professional for clinical accuracy. This guide does not constitute medical advice and is not a substitute for consultation with a qualified provider.

Last Updated: August 2026