During testosterone treatment, the main blood tests track testosterone itself, hematocrit and prostate cancer risk, alongside blood pressure checks. The 2018 Endocrine Society guideline suggests monitoring symptoms, side effects, adherence, serum testosterone, hematocrit and prostate cancer risk during the first year, and the testosterone cypionate label says hemoglobin and hematocrit should be checked periodically.
Tests before treatment starts
The cypionate label says to confirm low testosterone with morning serum testosterone measured on at least two separate days, both below the normal range. The Endocrine Society recommends a fasting, morning total testosterone with an accurate assay, repeated to confirm. Its full guideline text says about 30% of men with a first value in the low range have a normal value when it is measured again.
Baseline results also matter for safety. The Endocrine Society recommends against starting testosterone in men with PSA above 4 ng/mL (above 3 ng/mL in men at higher prostate cancer risk) without further urological evaluation, and in men with elevated hematocrit. These guidelines are recommendations, not laws.
Testosterone levels during treatment
The Endocrine Society suggests aiming for testosterone in the mid-normal range during treatment. The cypionate label says dosing is adjusted to the patient's response and adverse reactions. A licensed provider reads these results and makes any changes. This guide does not suggest a target or dose for any reader.
Hematocrit: why it gets so much attention
Several studies found testosterone raises hematocrit. A 2010 meta-analysis of 51 studies found a weighted mean increase of 3.18% (95% CI 1.35 to 5.01), though the evidence was low quality with short follow-up. A meta-analysis of 4 placebo-controlled trials (1,779 men) found a higher risk of erythrocytosis (relative risk 8.14, 95% CI 1.87 to 35.40).
Form may matter. A network meta-analysis of 29 trials found intramuscular enanthate or cypionate raised mean hematocrit 4.0% (95% CI 2.9 to 5.1), significantly more than the patch. In the T4DM trial, which used testosterone undecanoate injections, a hematocrit safety trigger above 54% occurred in 22% of the testosterone group versus 1% on placebo. The authors said hematocrit increases might be treatment limiting.
Prostate checks
The cypionate label lists known or suspected prostate cancer as a contraindication. A 2024 review of TRAVERSE prostate data says that, among men screened to exclude high prostate cancer risk, prostate cancer rates were low and did not differ from placebo, but PSA rose more on testosterone in year one. TRAVERSE used a testosterone gel, not cypionate.
FDA's Testosterone Information page (current as of 06/23/2026) says FDA requested label updates in June 2026 that include revising prostate cancer and BPH safety information. The revised wording was not available for this guide.
Blood pressure
The cypionate label says testosterone can raise blood pressure, which can increase cardiovascular risk over time, and says to monitor it. In its February 28, 2025 announcement, FDA said ambulatory blood pressure studies confirmed an increase with all testosterone products.
| Question | What the source says |
|---|---|
| Testosterone | Confirm low levels before starting; aim for mid-normal during treatment (Endocrine Society). |
| Hemoglobin and hematocrit | Check periodically during long-term use (cypionate label). |
| Prostate cancer risk | Part of first-year monitoring (Endocrine Society). |
| Blood pressure | Monitor (cypionate label). |
What this does not tell you
These sources do not set a single schedule for every man, and they do not say what any one reader's results mean. The hematocrit studies differ in form, dose and length, so their numbers cannot be compared directly. The prostate review covered men screened to exclude high risk, so it does not show what happens in higher-risk men. A licensed provider decides which tests are ordered, how often, and what to do with the results.