Why Bloodwork Is Non-Negotiable.
Flying blind on peptide protocols is not biohacking—it is gambling. Bloodwork before, during, and after protocols gives you objective data on whether the compounds are working, whether side effects are developing, and whether your baseline health markers are moving in the right direction.
The minimum standard: baseline labs before starting any protocol, then repeat at 8-12 weeks. For growth hormone secretagogues, add a midpoint check at 4-6 weeks because IGF-1 changes are detectable earlier and need monitoring.
Do not trust how you feel as a substitute for lab data. You can feel great while liver enzymes climb. You can feel sluggish while every biomarker improves.
The Baseline Panel: What to Order Before Starting.
Comprehensive Metabolic Panel (CMP): Covers liver enzymes (AST, ALT), kidney function (BUN, creatinine, eGFR), glucose, and electrolytes. This is your organ safety baseline.
Complete Blood Count (CBC): White blood cells, red blood cells, hemoglobin, hematocrit, platelets. Detects hematological shifts that peptides could influence.
Fasting Insulin and Glucose: Critical for MOTS-C and GLP-1 peptide protocols. You need pre-protocol insulin sensitivity data to measure metabolic impact.
IGF-1: Mandatory before any GH secretagogue protocol (CJC-1295, Ipamorelin, MK-677, Tesamorelin). IGF-1 is the downstream marker for growth hormone activity. Without a baseline, you cannot assess whether the secretagogue is working or how much GH signaling you are adding.
PSA (men over 40): Prostate-specific antigen baseline before growth-factor-active peptides. See our prostate health article for full rationale.
Thyroid Panel (TSH, free T3, free T4): Some peptides interact with thyroid function indirectly. Baseline values prevent misattribution of symptoms.
Lipid Panel: Fasting cholesterol, LDL, HDL, triglycerides. MOTS-C and metabolic peptides may influence lipid metabolism.
Post-Protocol Labs: What Changes to Look For.
IGF-1 elevation after GH secretagogues is expected and desired—within limits. A 30-50% increase from baseline is typical with CJC-1295/Ipamorelin. IGF-1 above 350 ng/mL in adults warrants dose reduction and discussion with a physician. Sustained elevation above 400 ng/mL increases theoretical cancer risk.
Fasting glucose and insulin: MOTS-C should improve these markers. GH secretagogues can temporarily increase fasting glucose due to GH's insulin-antagonist effects. A fasting glucose that rises above 100 mg/dL on GH peptides needs attention.
Liver enzymes (AST, ALT): Mild elevation (1.5-2x upper limit) can occur with some peptide protocols and usually resolves after cycling off. Persistent elevation above 2x warrants pausing the protocol and medical evaluation.
Kidney markers (creatinine, BUN, eGFR): Should remain stable. Significant changes may indicate dehydration, interaction effects, or underlying issues unrelated to peptides. Flag any shift to your physician.
CBC changes: GH secretagogues can mildly increase hemoglobin and hematocrit. If hematocrit exceeds 52% (men), assess hydration status first, then consider dose adjustment.
Timing Your Blood Draw.
Morning fasted (8-12 hours, water only) for accurate glucose, insulin, and lipid readings. Schedule the draw before taking any morning peptide doses.
For IGF-1 assessment on GH secretagogues: Draw blood 24-48 hours after your last GH peptide dose to capture the sustained IGF-1 signal rather than an acute spike.
For BPC-157 and TB-500 protocols: These peptides do not significantly alter standard blood markers, so timing is less critical. Use the same morning fasted window for consistency.
Avoid draws within 24 hours of intense exercise. Post-workout CK elevation and inflammatory marker changes can confound results.
Reading Your Results: What Is Normal, What Is Not.
IGF-1 reference ranges vary by age and lab. Generally: 115-307 ng/mL for ages 30-50. On GH secretagogues, expect the upper half or slightly above range. Flag anything above 350.
Fasting glucose: Under 100 mg/dL is normal. 100-125 is pre-diabetic range. GH peptides can push you into this range temporarily—monitor the trend, not a single reading.
ALT/AST: Lab-specific, but generally under 40 U/L for men. Under 33 U/L for women. Levels of 60-80 are worth noting. Above 80 needs investigation.
eGFR: Above 90 is normal. 60-89 is mild decrease. Below 60 requires medical attention regardless of peptide use.
Testosterone (total and free): BPC-157 and DSIP do not directly affect testosterone. GH secretagogues may modestly increase it. Kisspeptin protocols are designed to stimulate LH and testosterone—expect measurable increases.
Hematocrit: 38-50% for men. Above 52% warrants investigation, especially on GH secretagogues or if stacking with TRT.
How to Get Labs Without a Doctor.
Direct-to-consumer lab services (Marek Health, Quest via online portal, LabCorp patient access) allow you to order comprehensive panels without a physician order in most US states.
Cost: A basic peptide monitoring panel (CMP, CBC, IGF-1, fasting insulin, lipids, PSA) runs $150-250 through direct-to-consumer services. Some offer peptide-specific panels at a slight premium.
Frequency: Baseline before protocol. 8-12 week follow-up. Then every 3-6 months during ongoing use. Annually at minimum if cycling on and off.
◆ Key Takeaway
Baseline labs before every protocol. CMP, CBC, IGF-1, fasting insulin, PSA (men 40+), and lipids are the minimum panel. Repeat at 8-12 weeks. Monitor IGF-1 especially closely on GH secretagogues—flag anything above 350 ng/mL. Morning fasted draws, 24-48 hours after last GH peptide dose. Direct-to-consumer lab services run $150-250 per panel.