Testosterone Replacement Therapy (TRT)

The AUA's strongest-grade recommendation: low testosterone is diagnosed only after two total testosterone measurements, on separate occasions, both drawn in the early morning, with 300 ng/dL as the cutoff. The reason is biological, not bureaucratic — levels swing by 65–153% between tests, so a single afternoon draw tells you almost nothing. The guideline also calls for measuring LH to find out why levels are low, and checking hematocrit and (over 40) PSA before starting. A clinic that prescribes off one lab, or none, is not practicing to its own field's guideline — ask how many draws they require before you book.

Exogenous testosterone shuts down the signal that drives sperm production — the label itself warns that large doses may suppress spermatogenesis to the point of azoospermia. The AUA's guidance is unambiguous: testosterone should not be prescribed to men currently trying to conceive, the long-term impact on fertility must be discussed before starting, and men who want children should get a reproductive evaluation first. Alternatives that preserve fertility exist — hCG, SERMs, aromatase inhibitors — and a clinic that doesn't raise the fertility question before the first injection has skipped a guideline-mandated conversation.

Therapy done properly is therapy measured: testosterone levels every 6–12 months aiming for the middle of the normal range, hematocrit before starting and again at 3–6 months then annually (testosterone thickens blood), blood pressure checks now that the class-wide label warns of increases, and — the guideline's least-marketed recommendation — a conversation about stopping after 3–6 months if your levels normalized but your symptoms didn't improve. Two timing cautions from the guideline: no starting within 3–6 months of a cardiovascular event, and gel users must keep application sites covered from women and children.