The workup
Read your labs
What testosterone, SHBG, LH, FSH, insulin, HbA1c, and hs-CRP results mean on a men's health panel.
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You did the smart thing and got the workup. Now the results are a wall of numbers with reference ranges. Here's what the ones that matter actually mean: enough to have a real conversation with your clinician, not to diagnose yourself.
Reference ranges vary by lab and assay. A value outside the range isn't automatically a problem, and one inside isn't automatically fine. Symptoms, trend, and the whole picture decide, and that reading is your clinician's job.
The hormones
The headline number, but one value isn't a diagnosis. Because it swings by time of day and day to day, guidelines call for two early-morning (8–10 AM) draws on separate days before anyone concludes it's low.
The fraction actually available to your tissues. Most useful when total T is borderline, or when symptoms don't match the total, especially if SHBG is off. Not the primary diagnostic on its own. If your panel shows total T and SHBG but not free T, you can estimate it here.
The carrier protein that binds testosterone. High SHBG (aging, thyroid) ties up more T and lowers the free fraction; low SHBG tracks with insulin resistance and excess weight, so it's also a metabolic tell, not just a hormone footnote.
The pituitary's signals. If testosterone is low, these say where the problem is: high LH/FSH means the testes aren't responding (primary); low-or-normal LH/FSH with low T means the signal from the brain is down (secondary). It changes the whole workup.
Men need some estrogen. It's made from testosterone. Measured with a sensitive assay; both too-low and too-high cause problems, so it's read in context, not chased to a number.
High prolactin can suppress testosterone and cause ED (occasionally from a benign pituitary tumor), so it belongs in a low-T workup.
The metabolism (the drivers underneath)
A single snapshot of blood sugar after an overnight fast. Useful, but it moves later than insulin does.
Your roughly three-month average blood sugar. The standard screen for prediabetes and diabetes (American Diabetes Association criteria).
The early-warning pair. Insulin can run high while glucose still looks normal: the body compensating before sugar rises. HOMA-IR combines fasting insulin and glucose into one insulin-resistance estimate, and it often moves years before HbA1c does.
Standard cardiovascular risk: total, LDL, HDL, triglycerides. Triglycerides in particular track with insulin resistance.
A marker of low-grade inflammation used for cardiovascular risk. Above 10 usually means an active infection. Ignore it for risk until it settles.
Safety baselines (before & during treatment)
A prostate baseline your clinician establishes and monitors, particularly before and during testosterone therapy.
Testosterone therapy can thicken the blood by raising red-cell count, so hematocrit is a baseline and a monitored safety marker, not something to read in isolation. If yours is climbing, that has its own playbook: high hematocrit on TRT.
How to actually read it
- One number is a data point, not a verdict. Hormones especially need repeat, early-morning testing.
- Watch the trend. Retesting over time tells you more than any single panel, and keeps you on the smallest plan that works (see what it costs).
- The metabolic markers often speak first. Rising fasting insulin and falling SHBG can flag trouble long before glucose or testosterone look abnormal.
The bottom line
Your labs are a map, not a diagnosis. Knowing what each marker measures turns a passive handoff into a real conversation. You can ask better questions, catch the metabolic story early, and make decisions with your clinician instead of around them.
Sources & important note
Thresholds drawn from: AUA Testosterone Deficiency Guideline; StatPearls: Male Hypogonadism; Endotext: Assessing Insulin Sensitivity (HOMA-IR); and C-reactive protein in risk stratification. Glucose/HbA1c thresholds per the American Diabetes Association.
General education, not medical advice, and not a diagnostic tool. Interpret your results with a licensed clinician who knows your history.
Common questions
What blood tests are done for erectile dysfunction?
Typically an early-morning testosterone (repeated if it is low), blood sugar or HbA1c, a lipid panel, and sometimes thyroid or prolactin: screening the hormonal and metabolic drivers at the same time.
What counts as a normal testosterone level?
Normal is a range, not a number to maximize. A deficiency diagnosis rests on two low early-morning readings plus real symptoms, interpreted by a clinician against the rest of your labs. Never on a single value.
What is SHBG on a testosterone panel?
SHBG (sex hormone-binding globulin) is a protein that binds testosterone and keeps it in reserve. It explains why total and free testosterone can tell different stories, which is why both are worth reading together.