The guides
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Bloodwork
TRT blood test markers explained
What each of the twelve markers on a TRT panel measures, why it is followed, and what a reference interval actually represents.
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Pharmacokinetics
Injection frequency, peaks and troughs
Half-life, accumulation and peak-to-trough swing — with worked numbers from the same engine the app runs, and an honest list of what the model ignores.
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Safety marker
High hematocrit on TRT
Why therapy raises hematocrit, the thresholds written into guidelines, and the real difference between voluntary donation and therapeutic phlebotomy.
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Hormone panel
Estradiol (E2) on TRT
What controlled trials show about estradiol in men, why the sensitive assay matters, and why ratio targets from forums have no guideline behind them.
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Lab timing
When to draw your TRT panel
Morning fasting draws, trough versus mid-interval sampling, the monitoring windows guidelines describe, and the mundane things that ruin a panel.
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Bloodwork
Free testosterone and SHBG
How SHBG changes the free fraction, and how calculated, direct-analog and equilibrium-dialysis free testosterone differ enough to break a trend line.
How to use these with the calculators
Each guide pairs with one of the free browser tools, because a number is easier to understand when you can move the inputs and watch it change. Nothing is stored on a server, and none of them require an account.
- Dose & syringe calculator — Convert a prescribed mg dose to mL and insulin-syringe units for U-100, U-50 and U-40 barrels.
- Half-life & steady-state calculator — Chart accumulation across six weeks of injections: time to steady state and peak-to-trough swing.
- Blood donation & hematocrit planner — Project your hematocrit trend against the 42–52% band and the 56-day whole-blood interval.
A reasonable path through the material: start with what the markers mean, then when to draw them, then the specific marker you have a question about — estradiol, free testosterone and SHBG or hematocrit. The injection frequency guide explains why the timing of everything else matters in the first place.
What these pages will and will not do
TRT is a domain where confident bad information is abundant and cheap. The rules these pages follow are therefore deliberately narrow:
- Informational only. No dosing instructions, no protocol design, no "optimal" numbers, no promises about how you will feel.
- Primary sources, named. Clinical claims cite the Endocrine Society clinical practice guideline, AUA guidance, FDA-approved labelling on DailyMed, federal regulation, or peer-reviewed papers on PubMed — linked, so you can check them.
- Thresholds are attributed, not recommended. Where a guideline names a number, it is presented as something clinicians act on, never as an instruction to you.
- The clinician decides. TRT AI is a tracking tool. It records what you were prescribed and what your labs said; it does not calculate, recommend or adjust doses of anything.
- Dated and revisable. Every page carries a visible last-updated date, and guidelines get revised — read the current version.
If you are looking for a protocol, this is the wrong site. If you are looking to understand the numbers you already have well enough to ask better questions, keep reading.
Who writes this
These pages are written and maintained by the TRT AI editorial team — the people who build the app, not clinicians. That is exactly why they describe, cite and defer rather than advise. Nothing here has been reviewed as clinical guidance, and it should not be read as such.
Corrections are genuinely welcome, particularly on sourcing: contact@trtai.app.