Blood tests before, during and after a steroid cycle track the changes caused by exposure and how they develop after discontinuation. Comparisons rely on baseline results, the laboratory’s reference ranges and the conditions of each blood draw.
Monitoring involves three stages: establishing a baseline, checking the relevant parameters during exposure, then assessing their changes and hormonal recovery after discontinuation. The schedule takes into account the products used, symptoms and any existing abnormalities.
How to prepare for a blood test in bodybuilding
Keep conditions comparable between blood draws: time of day, usual hydration, sleep and time since your last training session. Report the medications, supplements and substances used, along with the dates they were last taken. Follow the laboratory’s instructions on alcohol and meals before testing.
Fasting according to the tests
When fasting is requested, it generally lasts 8 to 12 hours, with water only. A fasting blood glucose test requires it. For lipids, the conditions depend on the test order and the situation, particularly triglyceride levels. Confirm the laboratory’s instructions.
Consistent timing
A morning blood draw is particularly important when assessing natural testosterone production. During treatment or active exposure, also record the time since the last dose or injection. Keep this information with the report.
Intense training: allow an appropriate interval
An intense resistance training session increases CK and certain transaminases through muscle exertion. In the study by Pettersson and colleagues, AST and ALT remained elevated for at least seven days after a weightlifting session. This influence therefore sometimes persists despite 24 to 48 hours of rest.
For scheduled tests, agree on the rest interval with the ordering clinician, especially after an unfamiliar or particularly demanding session. In the presence of concerning symptoms or a significant abnormality, medical assessment remains the priority, even if preparation conditions are imperfect.
Which tests should be planned before a steroid cycle?
Baseline tests document health status before exposure. Personal values help measure changes; clinical thresholds and reference ranges remain essential for interpreting their significance. An existing abnormality requires assessment before any further exposure.
The table distinguishes the main test categories and additional tests suited to a specific question. The ordering clinician selects tests according to medical history, symptoms and the substances involved.
| Category | Baseline tests to discuss | Additional tests according to context |
|---|---|---|
| Hematology | Complete blood count (CBC), including hemoglobin, hematocrit and red blood cell count. | Ferritin, iron studies, vitamin B12 or folate to investigate an abnormal blood count. |
| Lipids | Total cholesterol, HDL, LDL, triglycerides and non HDL cholesterol. | ApoB to clarify the burden of atherogenic particles; Lp(a) to complement cardiovascular risk assessment. |
| Liver | ALT and AST, with GGT, bilirubin and alkaline phosphatase according to the panel ordered. | Albumin according to context; CK if a muscle source of the transaminases is being considered. |
| Kidneys | Creatinine, estimated glomerular filtration rate (eGFR), urea and electrolytes. | Cystatin C if the estimate based on creatinine is difficult to interpret; urinary albumin according to kidney risk. |
| Metabolism | Blood glucose according to risk and the products used. | HbA1c in the presence of diabetes risk or exposure to growth hormone. |
| Hormones | In men, morning total testosterone, LH and FSH when the goal includes establishing a hormonal baseline. | SHBG and calculated free testosterone according to the result; estradiol and prolactin according to symptoms and the clinical question. |
Blood pressure measurement complements these tests. Other tests address specific indications: TSH and free T4 for the thyroid, PSA according to age and prostate context, and IGF-1 in the case of growth hormone exposure. A fasting insulin test addresses a specific clinical question rather than being ordered routinely.
What the main blood markers show
Hematocrit and hemoglobin
Hematocrit is the proportion of blood volume occupied by red blood cells. Androgens stimulate their production. An increase is interpreted alongside hemoglobin, red blood cell count, hydration and previous values.
Dehydration concentrates the blood and raises the measured value. A persistent increase under usual hydration conditions warrants medical assessment, including investigation of other factors that influence red blood cell production.
HDL, LDL, non HDL and ApoB
Anabolic steroids alter the lipid profile, often with a decrease in HDL and an increase in LDL. Certain oral products cause pronounced changes. Non HDL cholesterol is calculated by subtracting HDL from total cholesterol; ApoB provides information about the number of atherogenic particles.
Cardiovascular assessment combines these results with blood pressure, smoking, blood glucose and family history. During monitoring, interpret changes in each marker in the relevant direction: a decrease in HDL and an increase in LDL are two different unfavorable changes.
ALT, AST, GGT and bilirubin
ALT and AST increase with liver injury, but also after intense muscle exertion. CK, GGT, bilirubin, alkaline phosphatase and the date of the last training session help interpret the observed profile.
Elevated CK after a session points to a muscular contribution. The full set of results and how they change remain necessary to investigate concurrent liver injury. Jaundice, dark urine or significant pain warrant prompt assessment.
Creatinine, eGFR and cystatin C
Creatinine depends on kidney filtration, but also on muscle mass, diet and certain supplements. In a very muscular person, eGFR calculated from creatinine therefore requires interpretation that accounts for these factors.
Cystatin C provides an estimate less dependent on muscle mass. Depending on the situation, a calculation combining creatinine and cystatin C improves accuracy. Measuring urinary albumin complements the assessment when kidney damage is suspected.
Testosterone, SHBG, LH and FSH
Total testosterone measures circulating testosterone. The result provides information about this hormone; the activity of other anabolic steroids requires a separate assessment. SHBG and, when needed, calculated free testosterone help refine the interpretation of a total testosterone value.
LH and FSH provide information about pituitary signals. Their suppression is expected during androgen exposure. After discontinuation, their changes alongside testosterone and symptoms help assess recovery of the hormonal axis.
Estradiol and prolactin
Estradiol contributes to sexual function and bone health, among other roles. Its measurement is interpreted alongside exposure to aromatizable products, the laboratory method and symptoms. Water retention, mood changes and sexual problems have several possible causes.
Prolactin is measured when a clinical question warrants it, for example in the presence of certain sexual problems or nipple discharge. Stress from the blood draw and medications also influence the result. An abnormality requires interpretation before any treatment decision.
Blood glucose and HbA1c
Blood glucose describes the glucose level at the time of the blood draw. HbA1c reflects the average level over the preceding two to three months. It therefore provides a different time perspective, particularly useful during growth hormone exposure or in the presence of metabolic risk.
Blood tests during a steroid cycle
During exposure, testing looks for deviations from baseline and abnormalities requiring management. Tests focus primarily on the CBC, lipids, liver, kidney function and blood pressure, with additions according to the products and symptoms.
- Oral products: particular attention to lipids and liver tests, depending on the compound.
- Androgen exposure: monitoring of hematocrit, hemoglobin and blood pressure.
- Aromatizable products: estradiol when its measurement addresses a clinical question.
- Growth hormone: blood glucose and HbA1c, with IGF-1 according to the monitoring goal.
The schedule depends on the substances’ duration of action, changes in exposure and previous results. To compare hormone measurements during injectable use, record the interval between the injection and the blood draw. An abnormality or symptom warrants an earlier check, regardless of how stable exposure is.
Blood tests after a cycle and after PCT
Monitoring after discontinuation has two goals: checking changes in general parameters and assessing independent hormone production. These two assessments sometimes follow different timelines.
Rechecking abnormalities
Compare the altered parameters with baseline results and their least favorable values during exposure. Monitoring of elevated hematocrit, a worsened lipid profile or a liver abnormality begins according to clinical need, at discontinuation or earlier.
Assessing hormonal recovery
In men, morning testosterone, LH and FSH are the main reference points. SHBG, free testosterone and estradiol complement the assessment according to the situation. A fertility goal adds semen analysis to monitoring.
Accounting for hCG and SERMs
Clomiphene and Tamoxifen modify signals within the hormonal axis while they are active. hCG stimulates LH receptors in the testes and increases testosterone production. Tests performed while taking these drugs provide information about the response during treatment.
To assess independent recovery, the clinician takes into account the last dose of each substance, its duration of action and active metabolites. Record the discontinuation dates of anabolic steroids, hCG and SERMs. Injectable preparations with a long duration of action prolong exposure after the final injection.
Low testosterone is confirmed with a repeat morning measurement under appropriate conditions, alongside interpretation of symptoms. Repeated results allow the trend to be tracked. Hormonal recovery and fertility recovery sometimes proceed at different rates.
Mistakes that complicate interpretation of blood tests
Limiting monitoring to hormones
Complement hormone assessment with the relevant cardiovascular, liver and kidney parameters. A satisfactory testosterone result leaves these aspects to be assessed separately.
Comparing different conditions
Check the time of day, requested fasting, recent training, time since the last dose and units. Using the same laboratory makes monitoring easier; if you change laboratories, account for differences in methods and reference ranges.
Changing several variables without recording them
Keep a record of the dates of changes to medications, supplements, diet and training. This timeline helps interpret a result, even when several factors have changed together.
Concluding recovery from a single value
The conclusion rests on symptoms, changes in several markers and any drug effects still present. Reassuring test results remain a partial snapshot of health status.
References
- Fasting for a Blood Test. MedlinePlus.
- Muscular Exercise Can Cause Highly Pathological Liver Function Tests in Healthy Men. Pettersson et al., 2008.
- Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. Bhasin et al., 2018.
- Essential blood testing in the patient using androgenic anabolic steroids: a clinical practice guideline for primary care. Gibbons et al., 2024.
- Fasting Is Not Routinely Required for Determination of a Lipid Profile. Consensus EAS/EFLM, 2016.
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease.
- Hemoglobin A1C (HbA1c) Test. MedlinePlus.
- Diagnosis and Management of Anabolic Androgenic Steroid Use. Anawalt, 2019.
