This is the question men ask most often before starting testosterone therapy, and the honest answer is more reassuring than it was a decade ago while still being more complicated than either side of the argument tends to admit.
Medically reviewed by Kent Cohen, MD, FACEP — Medical Director, Balanced Bodies: Longevity + Wellness Clinic. Last reviewed October 2026.
Where the worry came from
Around 2013 and 2014, several observational studies and one trial raised concerns about cardiovascular events in men taking testosterone. The FDA responded in 2015 by requiring a label change noting a possible increased risk and a lack of adequate evidence either way, and asked manufacturers to conduct a proper trial.
Those early studies had significant limitations — small numbers, observational designs, and populations that made cause and effect hard to separate. But the concern was real enough to warrant proper investigation, and that is what followed.
What the large trial found
A substantial randomised trial was conducted specifically to answer the cardiovascular safety question in men with diagnosed hypogonadism who also had existing cardiovascular disease or elevated risk. Its primary finding was that testosterone therapy did not increase the rate of major adverse cardiac events compared with placebo.
That is a meaningful result, and it changed the picture considerably. It is also not the same as “testosterone is good for your heart” — the trial was designed to test whether it caused harm, not whether it conferred benefit. Some secondary findings, including rates of atrial fibrillation and pulmonary embolism, warranted attention.
The reasonable summary: in men with a genuine diagnosis who are properly monitored, the cardiovascular concern that dominated the 2010s has not been borne out.
The conditions that matter in that sentence
“In men with a genuine diagnosis.” The evidence concerns men with confirmed testosterone deficiency. It says nothing about men with normal levels taking testosterone for performance or general optimisation, who were not studied and whose risk profile is not established.
“Properly monitored.” This is the part that gets skipped. Testosterone raises haematocrit — the proportion of your blood made up of red cells — in a substantial minority of men. Allowed to climb unchecked, that thickens the blood and is a genuine clinical concern. It is also entirely manageable, because it is detectable on a routine blood test and responds to a dose adjustment.
You cannot feel rising haematocrit. The only way to catch it is to measure it.
What should actually be monitored
At a minimum: testosterone levels, a full blood count including haematocrit, oestradiol, and PSA where appropriate given your age and history. Blood pressure and lipids belong in the picture too.
Our protocol is a recheck at six weeks after starting, then quarterly once stable. Monitoring labs are included in the $100 monthly cost rather than billed separately — partly because that is fairer, and partly because monitoring that costs extra is monitoring that gets skipped.
The comparison worth making
If cardiovascular safety is your concern, the relevant comparison is not testosterone versus nothing. It is monitored testosterone therapy versus the alternatives men actually choose: an online service that mails testosterone without ever drawing blood, or untreated symptoms.
The first carries the risk this article is about, without the mechanism for catching it. That is the actual hazard in the current market.
What to do with this
If you have existing cardiovascular disease, a history of clots, or significant risk factors, that belongs in the conversation before you start — not as a reason you cannot be treated, but as a reason the monitoring plan matters more.
And if your levels turn out to be normal, none of this applies, because you should not be taking testosterone. Our guide to low testosterone symptoms covers what else produces the same picture.
More on our approach on the TRT page. Book a free consultation or call (678) 919-4845.
Further reading
This article is general information, not medical advice, and research in this area continues to develop. Discuss your own cardiovascular history with your provider before starting any hormone therapy.
