Over the past year, we have analyzed thousands of blood work panels submitted by real users. Patterns have emerged — not in the marker values themselves, but in how the panels were collected. The same mistakes show up again and again, quietly undermining the value of what would otherwise be actionable data.
Here are the six most common blood work mistakes we observe, ranked by how much they affect your results.
1. Training Before the Draw
This is by far the most frequent and impactful mistake. Training within 48—72 hours of a blood draw causes measurable elevations in creatinine, AST, and CK. These markers leak from exercised muscle tissue into the bloodstream, creating a picture that looks like kidney stress or liver damage — when in reality, you simply trained too close to the draw.
We see this in roughly one in three submissions. A user with perfectly healthy kidneys shows up with creatinine at 1.3—1.5 mg/dL and AST at 60—80 U/L, and the report flags both as abnormal. The result: unnecessary worry, unnecessary follow-up testing, and sometimes even unnecessary medication changes.
The Fix
2. Incomplete Panels
The standard comprehensive metabolic panel (CMP) plus lipid panel leaves out three markers that are critical for AAS users:
- ApoB — the single best predictor of cardiovascular risk, and almost never included in standard lipid panels.
- Cystatin C — the only kidney marker unaffected by muscle mass. eGFR from creatinine systematically underestimates kidney function in athletes.
- GGT — the only liver enzyme that does not rise from muscle damage. When AST and ALT are elevated but GGT is normal, the source is likely muscle, not the liver.
Without these three markers, you are flying blind on cardiovascular risk, kidney function, and liver origin assessment. They cost around $40—80 total and provide more actionable information than the entire standard panel combined.
3. Testing at the Wrong Time
Timing errors fall into two categories, and both are common:
Not fasting. A non-fasted lipid panel is essentially useless. Triglycerides can spike 200—300% after a meal, LDL calculations become unreliable, and glucose readings say nothing about metabolic health. We estimate 15—20% of submitted panels are non-fasted based on implausibly high triglycerides combined with normal LDL.
Mid-cycle vs. post-cycle confusion. Users often test mid-cycle and then worry about lipid values that are expected to be suppressed. Low HDL and elevated LDL on 500 mg testosterone per week are pharmacological effects, not emergency signals. Conversely, testing post-cycle without waiting 6—8 weeks for recovery gives a misleading picture of your natural baseline.
When to Test
4. Not Establishing a Baseline
A single blood draw tells you where you are, not where you are going. Without a pre-cycle baseline, you cannot distinguish between:
- A marker that was always outside the standard range for you (some people naturally run creatinine at 1.2)
- A marker that changed because of your cycle
- A marker that drifted over time independent of compound use
Roughly 40% of new users submit their first panel already on cycle, with no baseline to compare against. This is understandable — most people discover GearCheck after starting. But if you are planning your first cycle, the single most valuable blood draw is the one you take before you pin anything.
5. Comparing Against Standard Ranges
This is not a mistake you make, but a mistake the lab makes for you. Standard reference ranges are calibrated on the general population — sedentary individuals, mixed ages, mixed health statuses. They are not designed for strength athletes.
A creatinine of 1.3 mg/dL is flagged as high by every lab in the country. For a 200-pound lifter with 170 pounds of lean mass, it is perfectly normal. An AST of 55 U/L gets a red flag. For someone who trains five days a week, it is expected.
Ignore the lab flags. Compare yourself against athletic reference ranges and, more importantly, against your own personal baseline.
6. Ignoring Blood Pressure
Blood work does not capture everything. Blood pressure is arguably the single most important health metric for AAS users, and it does not show up on any lab requisition form.
We see users obsess over a slightly elevated LDL while their blood pressure sits at 140/90 unaddressed. High blood pressure causes more cardiovascular damage than any lipid value, and it is completely within your control. A home cuff costs 30 euros and takes 30 seconds per day.
If you track nothing else between blood draws, track your blood pressure. It is more responsive to interventions, easier to measure, and more predictive of outcomes than almost any laboratory marker.