The U.S. Food and Drug Administration (FDA) is now requiring testosterone products to have labels with a general warning that they can cause venous thromboembolism, reports MedPage Today. Product labels will be required to carry a general warning about the risk of blood clots in the veins. Additionally, they should also carry a warning about those events as a possible consequence of polycythemia that is already included in the product information.

This change in labeling requirements comes as the result of an ongoing investigation by the FDA, evaluating the risk of stroke, heart attacks, and death due to use of FDA-approved testosterone products. The FDA is reevaluating because recent studies suggested an increased risk of cardiovascular events among groups of men prescribed testosterone therapy.

Despite asking for a change in the label, the FDA has not concluded that FDA-approved testosterone treatment increases the risk of stroke, heart attack, or death. The FDA is reminding patients that they should not stop taking prescribed testosterone products without first discussing any questions or concerns with their health care professionals. Testosterone advocates continue to argue that testosterone actually improves cardiac outcomes.

Testosterone is a hormone essential to the development of male growth and masculine characteristics. Testosterone products are FDA-approved only for use in men who lack or have low testosterone levels in conjunction with an associated medical condition. Examples of these conditions include failure of the testicles to produce testosterone because of reasons such as genetic problems, chemotherapy, or problems with brain structures like the hypothalamus or pituitary.