While taking testosterone-based HRT, your doctor will monitor your bloodwork for signs of polycythemia. If found, several treatment options are available.

Testosterone is responsible for many body functions. For instance, increases in testosterone can increase your level of red blood cells.

When red blood cell levels are too high, it can lead to poor circulation and an increased risk of high blood pressure, blood clots, stroke, and heart attack. This is called polycythemia, and it’s a risk linked to all testosterone use.

An excess of testosterone can cause your body to make more red blood cells. Raising your testosterone levels can sometimes lead to lead to polycythemia. Polycythemia makes it harder for your heart to circulate blood throughout your body, and it can lead to complications such as high blood pressure or stroke.

This risk can be higher with unregulated testosterone injections, such as those people use for bodybuilding.

Injected testosterone is associated with a higher chance of polycythemia than other forms of testosterone supplementation. Unregulated forms of injected testosterone can lead to spikes in testosterone levels and in red blood cell production. This can result in polycythemia.

Is testosterone-induced polycythemia reversible?

It’s typically possible to reduce testosterone-induced polycythemia. Treatment can help your body make less red blood cells. Changes to your testosterone use can also help.

Often, people who develop testosterone-induced polycythemia when taking prescribed testosterone are able to continue taking testosterone.

Polycythemia is one of the primary risks associated with prescribed testosterone. There is a risk when testosterone is prescribed as testosterone replacement therapy (TRT) to cisgender men for hypogonadism or for symptoms of low testosterone, such as reduced sex drive, fatigue, and loss of muscle mass.

Polycythemia is also a risk for transgender men taking testosterone as hormone replacement therapy (HRT). A 2021 study suggests that about 11.5% of transgender men receiving HRT develop polycythemia.

Estimates for cisgender receiving TRT range between 5% and 66%. In both groups, levels of red blood cells increase the most during the first year of treatment.

When you receive prescribed testosterone, your doctor will monitor your level of blood cells. Typically, you’ll have lab work done before you begin TRT or HRT to get a starting read on your level of red blood cells. Your primary medical professional will likely check your level again in about 3–6 months. They might follow up with additional tests every 6 months.

Polycythemia doesn’t always cause symptoms. It’s sometimes first noticed during lab testing. When symptoms do develop, they can include:

Without treatment, polycythemia can cause serious and even fatal complications. It’s linked to an increased chance of high blood pressure and heart health conditions. It can lead to heart attack, blood clots, and stroke.

Multiple treatment options exist for polycythemia. The exact treatment might depend on factors such as why you’ve been prescribed testosterone, the severity of your polycythemia, your overall health, and your age.

Common options include:

  • Changes to your testosterone prescription: Your doctor might change the dose or delivery of your testosterone medication. For instance, although all testosterone supplementation carries some risk of polycythemia, the risk is lower with options such as patches or pellets.
  • Therapeutic phlebotomy: During therapeutic phlebotomy, blood is removed from your body through an inserted intravenous (IV) line. The procedure is similar to donating blood. You might need to do this several times a year.
  • Lifestyle changes: Smoking and obesity can increase the risk of polycythemia. Your doctor might encourage you to quit smoking and achieve a healthy weight.

Polycythemia is a condition that happens when your body makes too many red blood cells. It’s a known risk of taking testosterone for any reason.

Polycythemia is linked to serious complications such as blood clots, stroke, and heart attack. Treatments such as lifestyle changes, medications, therapeutic phlebotomy, prescription adjustments, and surgery can help prevent these complications.