Know what’s happening beneath the surface.

The total amount of testosterone circulating in your bloodstream.

Helps confirm whether low testosterone (hypogonadism) is causing symptoms like chronic fatigue, low libido, brain fog, or loss of muscle mass.

Ensures your current treatment dose keeps your testosterone in an optimal, healthy range, avoiding levels that are either too low to be effective or unnecessarily high.

A chemical messenger sent from your brain’s pituitary gland instructing your testicles to produce testosterone naturally.

Helps your provider determine why your testosterone is low, whether the issue stems from the testicles or the brain’s signaling pathway.

When you take exogenous testosterone, your body pauses its natural production. As a result, your LH levels will naturally drop near zero. This is an expected effect of therapy.

The percentage of your blood made up of red blood cells.

Testosterone naturally stimulates the body to produce red blood cells. If hematocrit levels get too high (typically above 50–54%), your blood becomes thicker, which can increase strain on the heart. Monitoring this marker allows your provider to adjust your dose or recommend routine blood donation to keep your circulation healthy.

A protein produced naturally by the prostate gland.

Testosterone does not cause prostate issues, but it can accelerate existing growth. Checking your PSA before starting TRT establishes a healthy baseline, and regular monitoring ensures your prostate remains healthy throughout treatment.