Testosterone Review, Dosing and Monitoring Platform
A staged PHP-first workflow that states whether treatment criteria appear to be met, identifies the exact next action, and generates formulation-specific sample starting plans only after the minimum diagnostic and safety review is complete.
Start with the patient status
Choose the path that matches the clinical task. The new-patient path first confirms the diagnosis, then identifies the minimum information needed before treatment selection. The existing-patient path starts with the current regimen, response, draw timing, and follow-up safety labs.
Laboratory reference guide
Example adult male intervals from the supplied laboratory documents unless otherwise noted. The reporting laboratory, assay, age, clinical context, and product label take priority.
Open the full laboratory range table
| Test | Example adult male reference interval | Role | Important distinction |
|---|---|---|---|
| Total testosterone | 240-950 ng/dL | Core diagnostic and follow-up test | A common diagnostic reference near 300 ng/dL is not the laboratory lower limit or an on-treatment target. |
| Free testosterone | Age-specific: 5.25-20.7 ng/dL at 20-24; 4.06-15.6 at 50-54; 3.67-13.9 at 60-64; 3.28-12.2 at 70-74 | Conditional when SHBG is abnormal or total T is borderline or discordant | Method-specific. Equilibrium dialysis or validated calculation is generally preferable to a direct analog assay. |
| Bioavailable testosterone | 20-29: 83-257; 30-39: 72-235; 40-49: 61-213; 50-59: 50-190; 60-69: 40-168 ng/dL | Optional binding-context measure | Not interchangeable with free testosterone or every laboratory method. |
| SHBG | 13.3-89.5 nmol/L | Explains total/free T discordance and supports calculated free T | Not a stand-alone dose target. |
| LH | 1.3-9.6 IU/L | Core etiologic classification | Normal may be inappropriately normal when testosterone is low. |
| FSH | 1.2-15.8 IU/L | Fertility and testicular-function questions | Interpret with semen analysis and fertility goals. |
| Prolactin | 4.0-15.2 ng/mL | Conditional for secondary pattern or pituitary concern | Stress, sleep, medications, renal/thyroid disease, and macroprolactin can affect results. |
| Estradiol | 10-40 pg/mL | Conditional for gynecomastia, breast symptoms, or selected adverse effects | No automatic aromatase-inhibitor threshold is used. |
| Hemoglobin | 13.2-16.6 g/dL | Baseline and follow-up CBC component | Interpret with hematocrit and the full CBC. |
| Hematocrit | 38.3-48.6% | Core safety test | Lab range differs from pretreatment deferral >50% and on-treatment intervention >=54%. |
| PSA | <40: <=2.0; 40-49: <=2.5; 50-59: <=3.5; 60-69: <=4.5; 70-79: <=6.5; >=80: <=7.2 ng/mL | Shared-decision prostate monitoring when indicated | Absolute value, change, examination, risk, symptoms, and cancer history all matter. |
| Hemoglobin A1c | 4.0-5.6%; increased risk 5.7-6.4%; diabetes >=6.5% | General cardiometabolic assessment | Not a testosterone dose target. |
| DHT | 112-955 pg/mL | Nonroutine; selected 5-alpha-reductase questions | Serum DHT does not directly measure peripheral androgen action. |
| DHEA | 19-30 <13; 31-40 <10; 41-50 <8; 51-60 <6; >=61 <5 ng/mL | Nonroutine adrenal-androgen evaluation | Supplied source is DHEA, not DHEA-S; replacement monitoring is not established. |
| hs-CRP | <2.0 mg/L | Optional cardiovascular-risk context | Acute inflammation can invalidate a basal risk result; not a TRT threshold. |
| Homocysteine | Age-specific male interval; examples: age 30, 6.4-11.9; age 50, 6.8-15.0; age 70, 7.3-16.3 nmol/mL | Nonroutine nutritional or metabolic evaluation | Cardiovascular-risk role is uncertain and it is not routine TRT testing. |
| Zinc | 0.66-1.10 mcg/mL for age >=11 | Only when deficiency is suspected | Hemolysis can falsely elevate the result; trace-metal collection matters. |
| 1,25-dihydroxyvitamin D | 18-64 pg/mL for males age >=16 | Second-order testing | 25-hydroxyvitamin D is preferred initially for vitamin D stores in most patients. |
Full age-specific free testosterone examples
| Age | Free T, ng/dL | Age | Free T, ng/dL |
|---|---|---|---|
| 20-24 | 5.25-20.7 | 60-64 | 3.67-13.9 |
| 25-29 | 5.05-19.8 | 65-69 | 3.47-13.0 |
| 30-34 | 4.85-19.0 | 70-74 | 3.28-12.2 |
| 35-39 | 4.65-18.1 | 75-79 | 3.08-11.3 |
| 40-44 | 4.46-17.1 | 80-84 | 2.88-10.5 |
| 45-49 | 4.26-16.4 | 85-89 | 2.69-9.61 |
| 50-54 | 4.06-15.6 | 90-94 | 2.49-8.76 |
| 55-59 | 3.87-14.7 | 95+ | 2.29-7.91 |
Clinical background and evidence boundaries
Education remains near the decision point, with longer background material here.
New-patient sequence
- Confirm compatible symptoms or signs.
- Confirm two early-morning testosterone results obtained on separate days.
- Use LH, and FSH when relevant, to classify the pattern.
- Address illness, obesity, sleep, medications, nutrition, and reversible contributors.
- Clarify fertility before exogenous testosterone.
- Complete CBC/hematocrit, blood pressure, and prostate-risk review.
Existing-patient sequence
- Verify the original diagnosis and current product.
- Document actual dose, route, frequency, adherence, and technique.
- Interpret testosterone only in relation to product-specific draw timing.
- Trend hematocrit, blood pressure, PSA when indicated, symptoms, and adverse effects.
- Do not automatically increase dose or add an aromatase inhibitor based on one value.
- Reassess the diagnosis when testosterone is normalized but symptoms do not improve.
Microdosing and high-frequency splitting
Microdosing is a growing clinical trend. The central principle is to use the minimum effective weekly dose and divide it often enough to reduce peak-to-trough variation. Daily and every-other-day cypionate or enanthate protocols commonly use SQ administration because the individual volume is small and the injections may be easier to tolerate.
Twice-weekly and three-times-weekly regimens are already more stable than larger, less frequent boluses, but they do not eliminate the possibility of a low pre-dose trough. In susceptible patients, energy, libido, erections, mood, or other original symptoms may return quickly before the next administration. A consistently timed true trough and symptom diary are more useful than an isolated mid-cycle value.
More frequent administration may allow a lower weekly total in selected patients, but frequency and weekly dose are separate decisions. The existing-patient calculator provides 10% and 15% arithmetic scenarios for modest clinician-directed retitration. Daily dosing does not automatically require either reduction. An immediate 40% reduction is not presented because it may cause under-replacement and recurrence of symptoms.
The pharmacokinetic rationale is strong, but direct comparative trials of daily versus every-other-day versus twice-weekly administration for symptoms, safety, and long-term outcomes remain limited. Product labeling, route, dose-measurement precision, injection burden, adherence, cost, patient preference, and follow-up laboratory timing remain important.
Estradiol and DHT
Testosterone is converted to estradiol and DHT. Dose, age, body composition, SHBG, assay method, and formulation can influence measured concentrations. The application does not define a universal estradiol target or automatically recommend an aromatase inhibitor. DHT is not a routine dose target.
Current safety context
Current regulatory language no longer carries the older class-wide boxed-warning statement asserting increased major adverse cardiovascular outcomes after FDA review of TRAVERSE. Testosterone products retain the limitation of use for age-related hypogonadism, and FDA now requires class-wide blood-pressure warnings. Blood pressure is therefore a core baseline and follow-up variable.
TRAVERSE supports cardiovascular noninferiority for major cardiovascular events within the studied population and follow-up. It does not prove unrestricted lifetime safety.
Key current references
- Endocrine Society clinical practice guideline and 2026 statement on testosterone replacement therapy.
- U.S. Food and Drug Administration class-wide labeling changes for testosterone products.
- Current DailyMed labeling for the exact product used.
- Lincoff AM, et al. Cardiovascular Safety of Testosterone-Replacement Therapy. N Engl J Med. 2023.
- Lakshman KM, et al. Effects of injected testosterone dose and age on conversion to estradiol and dihydrotestosterone. J Clin Endocrinol Metab. 2010.