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Reading your first TRT blood test

The five numbers most people look at first, how they sit together, and the traps a first panel sets for everyone.

Updated 2026-11-08 · Part of the Magno guides

Your first panel on testosterone lands as a PDF with thirty rows, a few of them flagged in red, and no story. This is a plain-words tour of what the main numbers are and how they relate. It is not a plan; decisions belong to you and your clinician.

1. Where in the injection cycle was the draw?

A draw two days after a shot reads high on several markers: total testosterone, estradiol, hematocrit. A trough draw, the morning of the next injection, reads lower. If you do not know when the draw was relative to the shot, the numbers are hard to compare with anything. Drawing at the same point each time, at the same lab, makes later tests comparable.

2. Testosterone and its free fraction

Total testosterone above the lab range is common on TRT, especially at peak. Free testosterone is the part that acts on tissue, and SHBG explains the gap between the two. High SHBG means the total overstates what is available; low SHBG means the opposite.

3. Estradiol, next to testosterone

Estradiol makes more sense next to testosterone than on its own. Some people read it as a ratio, testosterone (ng/dL) divided by estradiol (pg/mL), and 15 to 30 is commonly quoted. A low ratio usually goes with big infrequent shots or more body fat; a high one with estradiol held down, often by an aromatase inhibitor. The sensitive estradiol assay reads men's levels more accurately than the standard one.

4. Hematocrit

This is the number doctors watch most closely on testosterone. It rises with the dose and the size of the peaks, and it reads higher when you are dehydrated. The Endocrine Society 2018 guideline treats a hematocrit above 54 percent as a reason to stop or adjust therapy, and lower lines such as 52 percent are also commonly quoted. A high or rising result is one to raise with your doctor.

5. Lipids, as a ratio too

Testosterone tends to nudge LDL up and HDL down. Total cholesterol divided by HDL captures both; under 3.5 is commonly quoted as a target and over 5 as higher risk. Your doctor reads the lipid panel next to your other risk factors.

Everything else

A mild rise in liver enzymes is often training, not the liver, unless GGT is up too. Creatinine often reflects muscle and creatine, not the kidney. PSA a little higher than before TRT is common in the first year. Fasting glucose and HbA1c matter if you use growth hormone or MK-677.

The trap

One panel is a snapshot. The second panel, drawn the same way, is where the story starts: what moved, by how much, since what change. Keeping every marker on one line with the change since last time is what makes that visible to you and your doctor.