???? Updated: May 2026⏱️ Read time: 11 minutes✓ Complete Lab Guide✓ By Compound TypeTable of ContentsQuick AnswerWhy Labs MatterBaseline Labs (Before Starting)Labs by Compound TypeWhen to TestInterpreting ResultsFAQ⚡ Quick AnswerEssential labs before any peptide protocol: Comprehensive metabolic panel (CMP), complete blood count (CBC), lipid panel, fasting glucose + HbA1c, thyroid (TSH), and sex hormones (testosterone, estradiol, LH, FSH). Add IGF-1 before GH peptides. Add liver enzymes before SARMs or steroids.When to retest: At 8 weeks (mid-protocol) and 16 weeks (end of first full cycle). Ongoing every 3–6 months for long-term users. Labs are not optional — they are how you know your protocol is working and how you catch problems early.3×When to Test: Baseline, Week 8, Week 16IGF-1Key Marker for GH Peptide EfficacyHbA1cKey Marker for GLP-1 EfficacyAST/ALTCritical Safety Marker for SARMsWhy Bloodwork Is Non-NegotiablePeptides work by modifying your body's hormonal and metabolic environment. Without baseline and follow-up bloodwork, you are operating blind — you can't know whether your protocol is working, whether you need to adjust doses, or whether something is going wrong. Labs serve three critical functions:Confirm safety: Catch any adverse effects (liver stress, lipid changes, hormonal disruption) before they become seriousConfirm efficacy: Objective proof your protocol is producing the intended metabolic changes (HbA1c down, IGF-1 up, testosterone improved)Guide dose adjustment: Optimal dosing is individual — bloodwork tells you whether to increase, maintain, or reduce your doseThe Rule of ThumbIf a compound is powerful enough to produce meaningful physiologic change, it is powerful enough to cause problems if used incorrectly. Bloodwork is what separates informed, safe use from guessing. It also gives you objective proof of the results you're achieving — motivating continued adherence.Baseline Labs (Before Starting Any Protocol)These labs apply to every person starting any peptide protocol, regardless of which compounds they plan to use:Universal Baseline PanelTestWhat It MeasuresWhy It MattersComprehensive Metabolic Panel (CMP)Glucose, kidney function (BUN, creatinine), liver enzymes (AST, ALT, ALP), electrolytes, proteinEstablishes kidney and liver baseline; catches pre-existing conditionsComplete Blood Count (CBC)Red cells, white cells, platelets, hemoglobin, hematocritBaseline blood health; catches anemia, infection, or clotting issuesLipid PanelTotal cholesterol, LDL, HDL, triglyceridesBaseline cardiovascular risk; GLP-1s improve, SARMs may worsenFasting Glucose + HbA1cCurrent blood sugar + 3-month averageEstablishes metabolic baseline; key efficacy marker for GLP-1 peptidesTSH (Thyroid)Thyroid stimulating hormoneThyroid affects metabolism; some peptides contraindicated in thyroid cancer historyTotal + Free TestosteroneAvailable and bound testosteroneBaseline hormonal health; SARMs suppress; fat loss often improvesEstradiol (E2)Primary estrogenImportant for both men (elevated in obesity) and women (menopausal status)LH + FSHPituitary hormones controlling sex hormone productionBaseline pituitary function; affected by SARMsAdditional Labs by Compound TypeGLP-1 Peptides (Semaglutide, Tirzepatide)Additional TestWhyWhenInsulin (fasting)Measures insulin resistance directly; key efficacy markerBaseline + week 16Lipase + AmylasePancreatitis screening — GLP-1s have rare pancreatitis associationBaseline; retest if severe abdominal pain developseGFR (kidney filtration)GLP-1s protect kidneys but screen function before useBaseline + week 16CalcitoninThyroid C-cell marker — GLP-1s have theoretical thyroid risk (MTC)Baseline; contraindicated if elevatedBody composition (DEXA or circumference)Objective fat loss and muscle preservation trackingBaseline + every 12 weeks✅ Key efficacy markers to watch: HbA1c (should fall 0.5–2%+), fasting glucose (should normalize), body weight, waist circumference. Safety markers: lipase, kidney function, calcitonin.GH Peptides (Ipamorelin, CJC-1295, Sermorelin, Tesamorelin)Additional TestWhyWhenIGF-1Primary efficacy marker for GH peptides — should rise with effective dosingBaseline + week 8 + week 16Fasting glucose + insulinGH can increase insulin resistance at high levels; monitor especially in T2DBaseline + week 8IGF-1 ceiling checkAvoid supraphysiologic IGF-1 elevation (>300–350 ng/ml) associated with cancer riskWeek 8 mandatory✅ Target IGF-1 range: Upper-normal for age (typically 150–300 ng/ml depending on age). If IGF-1 >300 ng/ml, reduce dose or frequency. If IGF-1 shows no increase at week 8, verify injection technique and fasting compliance.SARMs (Ostarine, LGD-4033, RAD-140, etc.)Additional TestWhyWhenAST + ALT (liver enzymes)SARMs can elevate liver enzymes — the most common adverse effectBaseline + week 4 + week 8 + 4 weeks post-cycleTotal + free testosteroneSARMs suppress testosterone — measure degree of suppressionBaseline + mid-cycle + 4 weeks post-cycle (recovery check)HDL cholesterolSARMs reduce HDL — most significant cardiovascular risk factorBaseline + week 8SHBGSARMs reduce SHBG; affects free testosterone calculationBaseline + week 8⚠️ Stop SARMs immediately and consult physician if: AST or ALT >3× upper limit of normal; testosterone drops below 200 ng/dl with symptoms; significant HDL reduction (>30% below baseline).When to Test: The Complete Testing ScheduleTimepointTests RequiredPurposeBefore starting (Baseline)Full universal panel + compound-specific additionsEstablish baseline; screen contraindications; reference pointWeek 4 (SARMs only)Liver enzymes (AST/ALT), testosteroneEarly safety check for SARMs; catch liver stress earlyWeek 8 (Mid-protocol)Full panel repeat + compound-specific markersConfirm safety; assess efficacy; guide dose adjustmentWeek 16 (End of cycle)Full panel + body compositionConfirm outcomes; document results; plan next cycle4 weeks post-cycleTestosterone, LH/FSH (SARMs/steroids); IGF-1 (GH peptides)Confirm hormonal recovery; verify return to baselineOngoing (long-term users)Full panel every 3–6 monthsChronic safety monitoring for continuous protocolsInterpreting Key ResultsMarkerDirection You WantRed Flag (Act Immediately)HbA1c↓ Decrease (GLP-1 efficacy)>8% or rising despite treatmentIGF-1↑ Rise into upper-normal range>300–350 ng/ml (supraphysiologic)AST / ALTStable or improving>3× upper limit of normalLDL cholesterol↓ Decrease (GLP-1 effect)Significant rise (>30% above baseline) with SARMsHDL cholesterol↑ Increase (GLP-1 effect)>30% drop from baseline (SARMs)Total testosteroneStable or rising126 mg/dl (diabetes range) if not already diabeticeGFR (kidney)Stable or improving