TRT Blood Work: Which Tests You Need and What They Mean (2026)
··8 mins
■ TL;DR — The Short Answer You need two morning total testosterone tests (7-10 AM, fasted, on separate days) below roughly 300 ng/dL, plus free testosterone, LH/FSH, estradiol, hematocrit, PSA, and SHBG. LH/FSH tell you whether the problem is in your testes or brain. On TRT, hematocrit is the most important safety marker — keep it under 54%. Follow-up labs at 6-12 weeks, then every 6-12 months once stable. Before starting TRT, you need two morning total testosterone tests (drawn between 7-10 AM, ideally fasted, on separate days) plus a supporting panel: free testosterone, LH/FSH, estradiol, hematocrit, PSA, and SHBG. Both the AUA and Endocrine Society require two low morning readings — generally below ~300 ng/dL — before diagnosing low testosterone. Here’s what every test means, what the numbers should look like, and how online clinics handle the whole process.