FDA Label Change on Approved Testosterone Products: Blood Clots Unrelated to Polycythemia

FDA Label Change on Approved Testosterone Products: Blood Clots Unrelated to Polycythemia

The U.S. Food and Drug Administration (FDA) has asked all manufacturers of FDA-approved testosterone products to include a warning about blood clots in the veins that are notrelated to polycythemia.

Polycythemia refers to increased levels of red blood cells and is a possible side effect of testosterone treatment. 

FDA-approved testosterone products already carry a warning about polycythemia-related blood clots. However, this most recent warning expands on that to include blood clots not associated with polycythemia.

In a statement released June 19, 2014, the FDA stated, “The risk of venous blood clots is already included in the labeling of testosterone products as a possible consequence of polycythemia, an abnormal increase in the number of red blood cells that sometimes occurs with testosterone treatment. Because there have been postmarket reports of venous blood clots unrelated to polycythemia, FDA is requiring a change to drug labeling of all testosterone products to provide a more general warning regarding venous blood clots and to ensure this risk is described consistently in the labeling of all approved testosterone products.”

Patients may see different terms used to describe blood clots:

  • Deep vein thrombosis (DVT) occurs when blood clots in a vein deep inside the body, such as in the thigh or in the lower leg. The blood clot is a clump of blood that can block blood flow through the vein.  If the blood clot separates and travels through the body on its own, it is called an embolus.
  • Pulmonary embolism (PE) occurs when an embolus travels to the lungs and blocks an artery there.  PE is a serious situation that can lead to organ damage or death.
  • Venous thromboembolism (VTE) is the term that describes DVT and PE when they happen together.

In February, the FDA announced a plan to review the safety of testosterone products after studies raised concerns about stroke, heart attack, and death. The new warning has nothing to do with this investigation.

Testosterone therapy is often prescribed to men whose bodies don’t produce enough testosterone on their own, a condition called hypogonadism.  Genetic issues and chemotherapy are other reasons a man might be treated with testosterone therapy.

Men who are concerned about the new FDA warning are encouraged to speak to their healthcare providers.



“Polycythemia (Elevated Red Blood Cell Count)”

(Reviewed: January 22, 2014)


Johns Hopkins Medicine

“What is DVT/VTE?”


National Heart, Lung, and Blood Institute

“What Is Deep Vein Thrombosis?”

(October 28, 2011)


U.S. Food and Drug Administration

“FDA adding general warning to testosterone products about potential for venous blood clots”

(June 19, 2014)