From the Guidelines

There is no established causal relationship between testosterone and hypertension (HTN).

The evidence suggests that higher testosterone levels may actually have a favorable effect on the risk of cardiovascular disease, including hypertension 1.
Some studies have reported increases in blood pressure with testosterone therapy, but the evidence is not consistent, and the overall effect on cardiovascular risk is still unclear 1.
A study of 32 men treated with supraphysiologic doses of testosterone found decreases in prothrombotic factors and no effect on platelet activity, suggesting a potential beneficial effect on cardiovascular health 1.
The American College of Physicians' evidence report found low-certainty evidence for the primary harm outcomes, including adverse cardiovascular events, and no significant difference in pooled risk for adverse cardiovascular outcomes between testosterone and placebo groups 1.
The evidence does not support a deleterious role of testosterone in the causation of cardiovascular disease, including hypertension, and some studies suggest that testosterone-replacement therapy may be beneficial for men with cardiac disease 1.

From the Research

The relationship between testosterone and hypertension (HTN) is complex and has been studied extensively.

Low testosterone levels have been inversely associated with hypertension in several studies 2, 3, 4.
Total testosterone, free testosterone, and sex hormone-binding globulin were found to be inversely associated with the prevalence of hypertension in a study of 5786 Chinese men 2.
Another study found that total testosterone was independently and inversely associated with central pulse pressure, wave reflections, and left ventricular mass in hypertensive men 3.
However, some studies have found that high testosterone levels may be associated with increased blood pressure and cardiovascular risk in certain populations, such as black South African men and women 5.
Testosterone replacement therapy has been found to have a beneficial effect on blood pressure in hypogonadal men, with significant reductions in systolic, diastolic, and pulse pressure 6.

Several factors can influence the relationship between testosterone and hypertension, including:

Age: Age >65 years or body mass index ≥24 may negatively impact the inverse correlation between testosterone levels and hypertension 2.
Smoking and family history of hypertension: These factors may strengthen the correlation between testosterone levels and hypertension 2.
Antihypertensive therapy: Testosterone replacement therapy may have a greater effect on blood pressure in men with higher baseline blood pressure or those on antihypertensive therapy 6.
Sex hormone-binding globulin: SHBG levels have been found to be higher in hypertensive men, and may be associated with an increased risk of hypertension 4.

The relationship between testosterone and cardiovascular risk is complex, and may depend on various factors, including:

Testosterone levels: Both low and high levels of testosterone may be associated with greater cardiovascular risk 2, 5.
Population: The relationship between testosterone and cardiovascular risk may vary depending on the population being studied, such as men versus women, or different ethnic groups 5.
Other risk factors: Other risk factors, such as smoking, family history of hypertension, and antihypertensive therapy, may also influence the relationship between testosterone and cardiovascular risk 2, 6.