What the Evidence Shows, and What We Watch
TRT is monitored, not assumed. Here is what gets checked, when, and why — including why elevation matters in Arizona and Utah.
Last reviewed 2026-10-04 by Lauren Orta, FNP-C, Family Nurse Practitioner. This page is clinical content and is reviewed on a regular schedule.
What gets monitored
| Marker | When | Why |
|---|---|---|
| Total & Free Testosterone | Baseline + follow-up | Confirms low levels and tracks response to dose |
| Hematocrit (CBC) | Baseline + during treatment | Testosterone can raise hematocrit; altitude raises it further |
| Estradiol | Baseline + follow-up | Testosterone aromatizes to estradiol; tracked to manage side effects |
| SHBG | Baseline | Affects free testosterone calculation |
| PSA (men over 40) | Baseline + follow-up | Prostate monitoring before and during treatment |
Why elevation matters
Testosterone therapy can increase hematocrit. Altitude also increases hematocrit, because the body produces more red blood cells in thinner oxygen. Men in high-elevation cities — Flagstaff and Prescott in Arizona; Park City, the Wasatch Front, and Cedar City in Utah — have two inputs moving the same number.
The American Urological Association's Testosterone Deficiency Guideline (Statement 11) directs clinicians to measure hemoglobin and hematocrit before starting treatment and during it. That is standard monitoring, not a reason to avoid treatment — it is a reason to be treated by someone who checks.
Source: American Urological Association, Testosterone Deficiency Guideline, Statement 11. See the full TRT and elevation guide for a city-by-city breakdown.
Who should not start TRT
Men with untreated severe sleep apnea, uncontrolled heart failure, a recent history of hormone-sensitive cancer, or markedly elevated hematocrit should not start TRT. This is not a complete list. See the eligibility page for more, and your provider reviews your full history before prescribing.