Lab Monitoring
Baseline
Baseline Labs Before Starting GLP-1
The blood work you need before your first injection -- establishing your starting point and screening for safety.
Last updated: April 1, 2026-10 min read
Before starting semaglutide or tirzepatide, baseline blood work establishes your metabolic starting point, screens for contraindications, and creates a benchmark for tracking the improvements that most patients experience.
Core Baseline Panel
Recommended Baseline Tests
| Test | What It Measures | Why It Matters |
|---|---|---|
| CMP (Comprehensive Metabolic Panel) | Kidney function, electrolytes, glucose | Screens kidney health; baseline glucose |
| Lipid Panel | Total cholesterol, LDL, HDL, triglycerides | Tracks cardiovascular risk improvement |
| HbA1c | 3-month average blood sugar | Identifies diabetes/prediabetes; tracks improvement |
| TSH | Thyroid function | Screens thyroid issues (GLP-1 boxed warning) |
| Liver Panel (ALT, AST, ALP) | Liver function | Baseline for monitoring; screens for liver disease |
| CBC | Red/white blood cells, hemoglobin | General health screen; anemia detection |
| Vitamin D | 25-OH Vitamin D level | Commonly deficient; important for bone health |
| Vitamin B12 | B12 level | Can decrease with reduced food intake |
| Fasting Insulin | Insulin resistance marker | Tracks insulin sensitivity improvement |
Additional Tests for Specific Patients
- PCOS patients: Testosterone, DHEA-S, SHBG, LH/FSH (hormone panel)
- Cardiovascular risk: CRP, Lp(a), apoB (cardiac panel)
- Over 60: DEXA bone density scan
- Iron/nutrient concerns: Ferritin, iron, folate, zinc (nutrient panel)
Red Flags in Baseline Labs
- - TSH abnormality: Must be evaluated before starting (thyroid risk)
- - Elevated lipase/amylase: Screen for pancreatitis risk
- - eGFR below 30: Severe kidney impairment requires dose adjustment discussion
- - ALT/AST greater than 3x upper limit: Liver disease evaluation needed first
- - Positive pregnancy test: GLP-1 medications contraindicated in pregnancy
Start with the Right Foundation
Trimi physicians order appropriate baseline labs for every patient. Semaglutide $99/mo. Tirzepatide $125/mo.
Get StartedMedical Disclaimer
Lab recommendations may vary based on individual medical history. Your healthcare provider will determine the appropriate tests for your situation.
More on GLP-1 lab monitoring
Sources & References
- Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. NEJM 2021;384:989-1002.
- Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. NEJM 2022;387:205-216.
- Lincoff AM et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. NEJM 2023;389:2221-2232.
- FDA Prescribing Information for Wegovy (semaglutide) and Zepbound (tirzepatide).