Why might a low-testosterone evaluation include another hormone, such as prolactin?

Because finding a low testosterone result and understanding why it is low are different tasks. In selected situations, another hormone test can help investigate the cause. Prolactin is one example; an abnormal result can have several explanations. MedlinePlus prolactin information.

This does not mean everyone needs the same expanded panel, or that an extra test means a serious diagnosis has already been found.

At MedFIT, additional testing should answer a useful question. Some findings may lead to specialist evaluation rather than simply starting or increasing TRT.

Next: Ask what the additional test is intended to clarify.