TRT and Heart Health

One of the most common concerns men have about TRT is its effect on the heart. Headlines over the past decade have swung between "testosterone causes heart attacks" and "testosterone protects the heart." Here's what the evidence actually shows.

Where the concern came from

In 2010, a small study in older men with significant mobility limitations found an increased rate of cardiovascular events in the testosterone group compared to placebo. This was followed by a 2013 retrospective study that suggested increased cardiovascular risk in men prescribed TRT. Both studies had significant methodological limitations, but they triggered widespread media coverage and prompted regulatory review.

In response, the US FDA required a large-scale randomised controlled trial — the TRAVERSE trial — to formally assess cardiovascular safety.

What the major trials found

The TRAVERSE trial, published in the New England Journal of Medicine, enrolled over 5,000 men aged 45–80 with hypogonadism and pre-existing or high risk of cardiovascular disease. The results showed that testosterone gel did not increase the rate of major adverse cardiovascular events (heart attack, stroke, or cardiovascular death) compared to placebo.

A comprehensive review published in peer-reviewed literature in 2025 concluded that TRT in men over 50 with confirmed hypogonadism offers significant benefits with a favourable safety profile under structured monitoring, and that safety data indicate no increased risk of major cardiovascular events when guidelines are followed.

A separate matched cohort study published in the Annals of Pharmacotherapy also found no difference in cardiovascular event rates between men on TRT and those not on TRT.

What TRT actually does to cardiovascular markers

When properly dosed and monitored, TRT has been shown to:

• Reduce total cholesterol and LDL in some studies
• Reduce systemic inflammation markers
• Improve insulin sensitivity and glycaemic control
• Reduce visceral fat (a major cardiovascular risk factor)

However, TRT also increases haematocrit (red blood cell count), which — if unchecked — can increase blood viscosity and clotting risk. This is the primary cardiovascular concern with TRT and the reason regular blood monitoring is essential.

The real risk: lack of monitoring

The cardiovascular risk from TRT is not inherent to the treatment itself — it comes from poor supervision. Men who take testosterone without proper blood work, without haematocrit monitoring, and without dose adjustment are at genuine risk. This is why unsupervised testosterone use (including self-prescribed testosterone from overseas or underground sources) is dangerous.

Properly supervised TRT — with regular monitoring of haematocrit, blood pressure, lipids, and PSA — has a strong safety profile. For a breakdown of what gets monitored and why, see TRT side effects.

Should men with existing heart disease use TRT?

Interestingly, the TRAVERSE trial specifically enrolled men with pre-existing cardiovascular disease or high cardiovascular risk — and still found no increased event rate. However, men with established heart disease should discuss TRT with both their GP and cardiologist, and monitoring should be more frequent.

According to the Heart Foundation, cardiovascular risk management should be individualised, and any new medication should be assessed in the context of overall cardiovascular risk.

The bottom line

The evidence does not support the claim that properly supervised TRT increases cardiovascular risk. The key words are "properly supervised" — regular blood work, haematocrit monitoring, and GP oversight are non-negotiable. This is exactly why our model requires ongoing clinical supervision for every patient on TRT.