Testosterone replacement therapy can raise blood pressure in some men, which is why the FDA added a new warning about it to every testosterone product label in 2025. But the picture is more complicated than a simple side effect: long-term data on steady-state testosterone therapy shows blood pressure improving in many hypogonadal men, especially those who started with high readings. The direction you're likely to see depends on your baseline health, your delivery method, and how closely your levels are monitored.
Does TRT Raise Blood Pressure?
It can, especially in the short term. On February 28, 2025, the FDA required class-wide labeling changes for all testosterone products after reviewing results from the TRAVERSE cardiovascular safety trial and required postmarket ambulatory blood pressure monitoring (ABPM) studies. The ABPM studies confirmed an increase in blood pressure with use of testosterone products across the class, and the new label now states that testosterone is not recommended for men with uncontrolled hypertension and that patients should have their blood pressure monitored regularly (FDA, 2025).
That warning grew out of the TRAVERSE trial, a study of 5,246 men aged 45 to 80 with hypogonadism and existing or high risk of cardiovascular disease who were randomized to daily transdermal testosterone gel or placebo. Testosterone therapy was found noninferior to placebo for major adverse cardiac events overall, but the trial also fed into the FDA's broader safety review that led to the blood pressure warning (Lincoff et al., New England Journal of Medicine, 2023).
Why Would Testosterone Raise Blood Pressure?
A few mechanisms are thought to contribute. Testosterone can cause the body to retain sodium and fluid, which increases blood volume. It also raises hematocrit, the concentration of red blood cells, which thickens the blood and increases resistance in the vessels the heart has to pump against. Delivery methods that create sharp peaks in testosterone level, such as infrequent large injections or pellets, tend to drive these effects harder than delivery methods that keep levels steady throughout the day or week.
This is also why blood pressure and hematocrit are usually checked together during TRT monitoring, since a rising hematocrit can be an early sign that fluid and blood volume shifts are underway (see our guide to monitoring TRT blood tests).
Can TRT Actually Lower Blood Pressure in Some Men?
Surprisingly, yes, at least in long-term registry data. A 2024 study followed 737 men with adult-onset testosterone deficiency for up to 96 months on injectable testosterone undecanoate, a long-acting formulation that maintains steady testosterone levels rather than producing sharp peaks. Among the 151 men who were never on blood pressure medication, median systolic and diastolic blood pressure fell by 12.5 and 8.0 mmHg respectively by the final assessment, with the largest improvements seen in men who started with the highest readings. Of the men already taking antihypertensive medication at baseline, 33 out of 202 were able to stop it during follow-up, while only 1 of 152 men not on such medication needed to start one (Hackett et al., World Journal of Men's Health, 2024).
The likely explanation is that correcting genuine testosterone deficiency improves body composition, insulin sensitivity, and vascular function over time, and those downstream effects can outweigh the fluid-retention effect, particularly with a steady-state delivery method used consistently for years rather than months.
Why Do the FDA Warning and the Long-Term Data Seem to Disagree?
They're not really contradicting each other, they're describing different time horizons and different populations. The FDA's warning is based on ABPM studies and the TRAVERSE trial, which capture blood pressure changes over a shorter window and across a range of delivery methods, some of which produce more pronounced peaks and fluid shifts. The registry data showing improvement followed one specific long-acting injectable formulation for up to eight years in a population being formally treated for diagnosed testosterone deficiency, not a general TRT-using population.
In practice, this means your own blood pressure trend on TRT will depend heavily on your delivery method, your dose, and how consistently your levels stay in a normal range rather than swinging between highs and lows.
