Starting a cycle without a complete blood work baseline is like navigating without a map. You need to know where you are before you can measure where you are going — and more importantly, you need to be able to recognize danger signals when they appear.
Below is the complete pre-cycle blood work checklist. This is not a suggestion — it is a minimum safety requirement.
1. Kidney Markers
Exogenous androgens stress the kidneys through increased muscle mass, elevated blood pressure, and direct metabolic effects. A pre-cycle kidney baseline is essential.
- eGFR (estimated glomerular filtration rate) — Your baseline kidney function. Above 90 mL/min/1.73m² is ideal. Monitor for drops > 10% during cycle.
- Serum creatinine — Expected to be slightly elevated in athletes due to muscle mass. Use with Cystatin C for a more accurate picture.
- Cystatin C — Optional but highly recommended. Not affected by muscle mass, so it gives a truer eGFR in athletes. The difference between creatinine-based and cystatin-based eGFR can reveal how much of your creatinine elevation is muscle vs. kidney stress.
- BUN (blood urea nitrogen) — A baseline for protein metabolism and hydration status.
- Urine albumin-to-creatinine ratio (UACR) — Optional but valuable for detecting early kidney damage before eGFR drops.
2. Liver Markers
Oral androgens are particularly hepatotoxic. A liver baseline is critical, especially if you plan to use oral compounds.
- AST (aspartate aminotransferase) — Found in both liver and muscle. Elevated in athletes from training alone. Context matters.
- ALT (alanine aminotransferase) — More liver-specific than AST. A better indicator of hepatic stress.
- GGT (gamma-glutamyl transferase) — Highly liver-specific. If GGT is normal, elevated AST/ALT are likely from muscle, not liver.
- ALP (alkaline phosphatase) — Biliary marker. Can be elevated during periods of bone remodeling or liver stress.
- Total and direct bilirubin — Elevated bilirubin indicates impaired liver clearance or Gilbert's syndrome (benign).
Incomplete Liver Panel
Many standard metabolic panels only include AST and ALT. Without GGT, you cannot distinguish muscle-derived elevation from liver-derived elevation. If your pre-cycle panel does not include GGT, request it separately. It is a cheap and essential test.
3. Cardiovascular Markers
AAS are known to negatively impact the lipid profile. Knowing your baseline is critical for assessing the impact.
- Total cholesterol — Less important on its own, but provides context.
- HDL cholesterol — The marker most impacted by AAS. A baseline above 40 mg/dL (1.0 mmol/L) gives you more room to drop before reaching dangerous territory.
- LDL cholesterol — Usually rises on cycle. Baseline helps quantify the increase.
- Triglycerides — Can rise on cycle, especially with orals. Fasted measurement is essential.
- ApoB (apolipoprotein B) — The single best predictor of atherosclerotic risk. Every particle that can cause plaque contains one ApoB molecule. If you only get one advanced lipid test, make it this one.
- Lipoprotein(a) (Lp(a)) — Optional but valuable one-time measurement. Lp(a) is genetically determined and does not change much, but high Lp(a) means you need to be more aggressive about managing LDL and ApoB.
4. Hematology
Androgens stimulate erythropoietin (EPO) production, increasing red blood cell mass. This is one of the most consistent and dose-dependent effects of AAS use.
- Hemoglobin (Hgb) — Baseline for oxygen-carrying capacity.
- Hematocrit (Hct) — The percentage of blood volume occupied by red blood cells. Baseline above 45% means less headroom before reaching donation thresholds.
- Red blood cell count (RBC) — Tracks with hematocrit.
- Platelets — AAS can increase platelet reactivity. Very high platelets combined with high hematocrit increases thrombotic risk.
- White blood cell count (WBC) with differential — Baseline immune function.
- Ferritin and iron panel — Especially important if you plan to donate blood to manage hematocrit. Donating with low ferritin can cause iron deficiency.
5. Hormones
Your natural hormonal baseline is essential for understanding how well (and how quickly) you recover post-cycle.
- Total testosterone (TT) — Your natural production level. Critical for calculating suppression and recovery.
- Free testosterone — Provides context for SHBG and bioavailable T.
- SHBG — Your natural SHBG level. Already discussed in detail in a dedicated article.
- Estradiol (E2) — Your natural E2 level and aromatization baseline.
- LH (luteinizing hormone) — Ideally 4-10 mIU/mL in a healthy natural male. This is your body's signal to produce testosterone. Post-cycle, LH recovery is the key indicator that your HPTA is waking up.
- FSH (follicle-stimulating hormone) — Supports spermatogenesis. Important for fertility considerations.
- Prolactin — Especially important if using 19-nor compounds (trenbolone, nandrolone), which can elevate prolactin.
6. Thyroid
AAS can suppress thyroid-binding globulin (TBG) and affect thyroid hormone levels. A pre-cycle thyroid baseline helps distinguish AAS effects from actual thyroid disease.
- TSH (thyroid-stimulating hormone) — The primary screening test for thyroid function. Aim for 0.5-2.5 mIU/L.
- Free T4 — Confirms thyroid hormone production.
- Free T3 — The active thyroid hormone. Optional but valuable if you have symptoms of hypothyroidism.
7. Metabolic Markers
Insulin resistance can develop or worsen on cycle, especially with certain compounds and bulking diets.
- Fasting glucose — Baseline blood sugar. Above 100 mg/dL (5.6 mmol/L) warrants further investigation.
- HbA1c (hemoglobin A1c) — 3-month average of blood sugar. Below 5.4% is optimal; 5.4-5.6% is acceptable; above 5.7% is prediabetic.
- Fasting insulin — Optional but very valuable. High fasting insulin with normal glucose indicates insulin resistance years before glucose rises.
- HOMA-IR — Calculated from fasting glucose and insulin. A score above 2.0 suggests insulin resistance.
8. Vital Signs and Subjective Data
Blood work alone does not tell the full story. Document these before starting:
- Blood pressure — Measure at rest, seated, after 5 minutes of quiet sitting. Take 3 readings and average them. Systolic above 130 or diastolic above 80 needs attention before cycle.
- Resting heart rate — Baseline cardiovascular fitness.
- Body weight — Weigh at the same time of day, same conditions.
- Body fat estimate — Useful context for interpreting blood markers.
- Baseline symptoms — Document any existing joint pain, sleep quality issues, mood patterns, or libido levels so you can track changes.
Sample Pre-Cycle Panel (Recommended)
If you can only afford one comprehensive panel, request the following from your provider:
- CMP (comprehensive metabolic panel) — includes eGFR, creatinine, BUN, glucose, AST, ALT, ALP, bilirubin
- Lipid panel — total cholesterol, HDL, LDL, triglycerides
- ApoB (add-on)
- CBC with differential
- Total and free testosterone
- Estradiol (sensitive, LC/MS-MS)
- SHBG
- TSH
- HbA1c