This article is for educational and research purposes only. Nothing here constitutes medical advice. All bloodwork should be ordered and interpreted by a licensed healthcare provider.
Why Bloodwork Is Essential
Bloodwork is the only objective way to measure what peptides are actually doing inside your body. Subjective feelings — better sleep, more energy, improved recovery — are useful but unreliable. Blood markers provide hard data that can confirm whether a peptide is having the expected physiological effect and whether it is causing any unintended consequences.
Baseline Panel (Before Starting)
Before using any peptide, establish baseline values for the following markers:
- Complete Metabolic Panel (CMP): Liver enzymes (ALT, AST), kidney function (BUN, creatinine), electrolytes, and blood glucose.
- Complete Blood Count (CBC): Red blood cells, white blood cells, platelets, and hemoglobin. Establishes your hematological baseline.
- Fasting insulin and glucose: Critical for detecting insulin resistance, which some peptides may affect.
- HbA1c: Three-month average blood sugar. Important if using GH secretagogues, which can impair glucose metabolism.
- IGF-1: Insulin-like growth factor 1. This is the primary marker for assessing growth hormone activity. GH secretagogues should raise IGF-1 levels.
- Lipid panel: Total cholesterol, LDL, HDL, and triglycerides.
- Thyroid panel: TSH, free T3, and free T4. Some peptides may interact with thyroid function.
- Hormone panel: Testosterone (total and free), estradiol, DHEA-S. Relevant for both men and women.
Follow-Up Testing Schedule
After establishing baseline values, retest at regular intervals:
- 4-6 weeks: First follow-up. Check IGF-1 (if using GH secretagogues), fasting glucose, insulin, and any markers relevant to your specific peptide.
- 12 weeks: Comprehensive retest including the full baseline panel. This gives enough time for most peptide effects to manifest.
- Post-cycle: Retest 4-6 weeks after discontinuing a peptide to confirm your markers return to baseline.
Peptide-Specific Markers
Different peptides affect different systems. If using GH secretagogues, IGF-1 and fasting glucose are critical. If using GLP-1 agonists, focus on HbA1c, fasting insulin, and lipid panels. If using peptides with potential anti-inflammatory effects (like BPC-157), C-reactive protein (CRP) and ESR may be useful markers to track.
How to Order Bloodwork
The ideal path is through your primary care provider or an endocrinologist. If your provider is unwilling to order specific tests, direct-to-consumer lab services allow you to order bloodwork without a physician's order. Always fast for 10-12 hours before blood draws for accurate glucose, insulin, and lipid results. Draw blood at the same time of day for each test to minimize diurnal variation.