Last reviewed: May 2026
Most GLP-1 telehealth programs don’t include lab work. They prescribe the medication, ship it monthly, and leave the monitoring to you and a physician you may never speak to again after the intake form. For a class of drugs that affects blood glucose, lipid metabolism, kidney function, liver enzymes, and thyroid markers — and that has specific contraindications a physician needs to watch for — that’s a meaningful gap.
If you’re starting GLP-1 therapy, lab work is the difference between “I think I’m doing well” and “my physician can see what’s happening clinically.” This guide covers exactly which labs your physician should be running, when, and what each marker tells them about your metabolic health.
Why Lab Work Matters on GLP-1 Therapy
GLP-1 medications — semaglutide, tirzepatide, and others — do more than reduce appetite. They directly affect:
- Blood glucose regulation. GLP-1 receptor agonists improve insulin sensitivity and reduce glucose production by the liver. For patients with type 2 diabetes or prediabetes, this is therapeutic. For patients without diabetes, it’s still worth tracking.
- Lipid metabolism. Most patients see improvements in LDL cholesterol, triglycerides, and HDL. Some see unexpected changes that warrant adjustment.
- Kidney function. Weight loss generally improves kidney markers, but rapid weight loss combined with reduced fluid intake can stress the kidneys in vulnerable patients.
- Liver enzymes. GLP-1 therapy often improves liver health markers in patients with metabolic dysfunction-associated steatotic liver disease (MASLD, formerly NAFLD), but baseline and ongoing monitoring catches anything unusual.
- Thyroid markers. GLP-1 medications carry a boxed warning regarding medullary thyroid carcinoma (MTC). Routine thyroid monitoring is standard for any patient on GLP-1 therapy.
- Pancreatic enzymes. Pancreatitis is a rare but serious adverse event associated with GLP-1 therapy. Baseline lipase establishes a reference point if symptoms ever emerge.
None of this is visible on a bathroom scale. Patients who treat GLP-1 therapy as a prescription rather than a clinical program miss the data that makes the program safely titratable over time.
A complete lab and medication record also matters at moments your prescribing program may not be the primary clinician — most commonly when surgery or another procedure is scheduled and every active medication needs to be disclosed to the surgical team. We cover the full disclosure protocol in our guide to GLP-1 use before surgery.
Baseline Labs: What You Should Get Before Starting
Before your first GLP-1 dose, your physician should establish a clinical baseline. The standard panel includes:
- Hemoglobin A1c (HbA1c) — three-month average blood glucose
- Fasting glucose — current blood sugar
- Comprehensive metabolic panel (CMP) — electrolytes, kidney function (BUN, creatinine, eGFR), and liver enzymes (AST, ALT, alkaline phosphatase, bilirubin)
- Lipid panel — total cholesterol, LDL, HDL, triglycerides
- Thyroid stimulating hormone (TSH) — thyroid function baseline; some programs add free T4 and free T3
- Lipase — baseline pancreatic enzyme to reference if pancreatitis symptoms ever emerge
- Complete blood count (CBC) — overall health screen
- Vitamin D, vitamin B12, and ferritin — nutrient status, which becomes especially relevant as appetite decreases and intake drops
Some programs add optional markers like hsCRP (inflammation), uric acid, fasting insulin, or HOMA-IR (insulin resistance calculation). These add clinical depth but are not standard.
If your physician is prescribing without ordering this baseline panel — or relying on labs you had years ago for an unrelated visit — that’s a meaningful clinical gap. GLP-1 therapy is not aspirin. The starting picture matters.
The Quarterly Labs Schedule on GLP-1
For ongoing GLP-1 therapy, the consensus clinical practice is quarterly metabolic labs — every three months. The reasoning is straightforward: GLP-1 dose titration typically happens over the first 16–20 weeks, and metabolic improvements (or unexpected changes) show up on lab panels within that window. Quarterly cadence catches the trends without over-testing.
A typical quarterly panel includes HbA1c, fasting glucose, CMP, lipid panel, and TSH. Vitamin D, B12, and ferritin are often added every 6–12 months unless deficiencies are flagged. Lipase is repeated only if symptoms warrant.
After the first year, some physicians shift to semi-annual labs if the patient is stable, medication is well-tolerated, and lab trends are clean. Patients with metabolic disease (diabetes, MASLD, dyslipidemia) often stay on the quarterly schedule indefinitely.
What Each Lab Marker Tells Your Physician
Hemoglobin A1c (HbA1c) and fasting glucose
HbA1c reflects your average blood sugar over the previous 2–3 months by measuring glycated hemoglobin in red blood cells. Normal is below 5.7%, prediabetic is 5.7–6.4%, and diabetic is 6.5% or higher. On GLP-1 therapy, HbA1c typically improves by 0.5–1.5 percentage points over 3–6 months in patients with elevated baselines. In patients without diabetes, HbA1c may remain in the normal range but often drifts toward the lower end.
Fasting glucose is a snapshot of your blood sugar after an overnight fast. Normal is below 100 mg/dL, prediabetic is 100–125 mg/dL, and diabetic is 126 mg/dL or higher. GLP-1 therapy typically improves fasting glucose alongside HbA1c.
If your HbA1c is dropping too fast in a patient on other diabetes medications (especially insulin or sulfonylureas), your physician needs to adjust those medications to prevent hypoglycemia. This is one of the most common reasons GLP-1 therapy needs active management, not just a prescription.
Lipid panel
LDL cholesterol, HDL cholesterol, triglycerides, and total cholesterol. GLP-1 therapy typically improves all of these — LDL and triglycerides decrease, HDL stabilizes or improves modestly, and the LDL:HDL ratio often shifts favorably. If your lipid panel is moving in the wrong direction during weight loss, that’s a signal worth investigating (rapid weight loss can transiently elevate certain markers in some patients).
Comprehensive metabolic panel (CMP)
The CMP includes:
- Electrolytes (sodium, potassium, chloride, CO2) — electrolyte imbalances can develop in patients with significant GI side effects (nausea, vomiting, diarrhea) on GLP-1 therapy.
- Kidney function (BUN, creatinine, eGFR) — weight loss generally improves kidney function in metabolically compromised patients, but rapid weight loss with poor hydration can stress the kidneys.
- Liver enzymes (AST, ALT, alkaline phosphatase, bilirubin) — GLP-1 therapy typically improves liver enzymes in patients with MASLD, but baseline values and trends matter for any patient.
Thyroid function (TSH, free T4)
GLP-1 medications carry a boxed warning regarding medullary thyroid carcinoma (MTC) based on rodent studies. The clinical relevance in humans is debated, but the standard of care is to screen for personal or family history of MTC and Multiple Endocrine Neoplasia syndrome type 2 (MEN2) before starting therapy, and to monitor thyroid function during therapy. New thyroid nodules, unexplained neck mass, persistent hoarseness, or difficulty swallowing should prompt immediate evaluation.
TSH is the primary screening marker. Free T4 and thyroid antibodies (TPO, thyroglobulin) are added if TSH is abnormal or if your physician suspects underlying thyroid dysfunction.
Pancreatic enzymes (lipase, amylase)
Pancreatitis is a rare but serious adverse event associated with GLP-1 therapy. Baseline lipase establishes a reference point. Repeat testing is typically only done if symptoms emerge — severe abdominal pain, especially radiating to the back, with nausea and vomiting. Patients with a history of pancreatitis or active gallbladder disease are generally not candidates for GLP-1 therapy.
Vitamin D, vitamin B12, and iron studies
Reduced food intake on GLP-1 therapy means reduced micronutrient intake, even when total protein and macronutrients are adequate. The deficiencies most commonly seen are:
- Vitamin D — common in the general population, often worsens with reduced dairy and fortified food intake
- Vitamin B12 — particularly in patients reducing meat intake or with reduced gastric acid (slowed gastric emptying on GLP-1 may further reduce B12 absorption)
- Iron — ferritin reflects iron stores; serum iron and transferrin saturation reflect current iron status
Targeted supplementation addresses deficiencies. Many GLP-1 patients benefit from a clinician-curated supplement protocol — protein, vitamin D, B12, magnesium, and electrolytes are common. See our guide to the GLP-1 nutrition gap for the detailed framework.
Inflammatory markers (hsCRP)
High-sensitivity C-reactive protein (hsCRP) is a marker of low-grade systemic inflammation associated with metabolic disease, cardiovascular risk, and obesity-related conditions. Not all programs include hsCRP, but it’s useful: many GLP-1 patients see their hsCRP drop significantly within 6 months of starting therapy, which correlates with cardiovascular risk reduction beyond what weight loss alone explains.
What Most GLP-1 Programs Skip
The cheapest medication-only GLP-1 telehealth services include none of the above. They issue a prescription based on an intake form, ship the medication monthly, and the relationship ends there. Lab work is “your responsibility” — meaning, for most patients, it doesn’t happen.
Some programs offer labs as an upgrade or a separate service, charged additionally. This means most patients skip them. A few programs include a single baseline panel but no ongoing monitoring — useful for screening contraindications, useless for tracking how your body is actually responding to therapy.
The result is that millions of patients on compounded GLP-1 medications are essentially self-managing a complex metabolic intervention with no clinical data. When something does go wrong — persistent side effects, plateau, unexpected lab abnormality on a routine visit elsewhere — their prescribing service often can’t help because they have no baseline to compare against.
What to Do If Your Current Program Doesn’t Include Labs
If you’re on a GLP-1 program without included lab work, you have three options.
Option 1: Ask your prescribing physician to order labs. Most telehealth physicians can order labs through Quest Diagnostics or Labcorp even if labs aren’t part of the standard subscription. You’ll typically pay out of pocket for the labs themselves — a comprehensive GLP-1 panel runs roughly $150–$300 cash-pay, less if billed through insurance.
Option 2: Order labs through a direct-to-consumer service. Services like Quest’s MyQuest, Labcorp OnDemand, Marek Health, or Function Health let you order your own labs without a physician. You’ll get the results but won’t have a physician to interpret them in the context of your GLP-1 therapy — which is a real limitation.
Option 3: Switch to a program that includes labs. Full-program GLP-1 telehealth services include quarterly labs in the monthly price along with ongoing physician oversight and coaching. The total cost is typically less than buying medication-only services and ordering labs separately, and the labs are interpreted by the physician who’s prescribing the medication.
How Elara Handles Lab Work
Elara Health and Wellness includes quarterly metabolic labs in every monthly subscription — not as an upgrade, not as an add-on. The panel includes HbA1c, fasting glucose, comprehensive metabolic panel (kidney and liver function), lipid panel, TSH, and additional markers as clinically indicated. Labs are drawn at Quest Diagnostics or Labcorp locations nationwide, and your board-certified physician reviews each panel with you to adjust your protocol.
This is a deliberate structural choice. The cheapest GLP-1 telehealth services compete on medication price alone. Elara competes on what the medication is part of — a real medical program with the clinical monitoring that makes GLP-1 therapy safer and more effective over time.
Learn more about Elara’s GLP-1 program or take our 5-minute assessment to see if compounded therapy might be appropriate for you.
Frequently Asked Questions
What labs should I get before starting GLP-1?
The standard pre-treatment panel includes HbA1c, fasting glucose, comprehensive metabolic panel (CMP), lipid panel, TSH, lipase, complete blood count (CBC), and vitamin D / B12 / ferritin. A licensed physician should order and review these before issuing your first prescription.
How often should I get labs on GLP-1?
Standard clinical practice is quarterly metabolic labs — every three months — for the first year. After that, some physicians shift to semi-annual labs if you’re stable. Patients with diabetes, MASLD, or dyslipidemia typically stay on the quarterly schedule indefinitely.
Do I need labs if I’m on compounded semaglutide or tirzepatide?
Yes. The medication is the same active pharmaceutical ingredient as the brand-name versions and affects the same metabolic markers. The regulatory pathway is different; the clinical monitoring requirements are not.
How much does GLP-1 lab work cost?
A comprehensive GLP-1 lab panel runs roughly $150–$300 cash-pay through Quest Diagnostics or Labcorp, often less if billed through insurance. Full-program GLP-1 telehealth services that include quarterly labs typically don’t itemize the cost — it’s bundled into the monthly price.
Can my physician adjust my GLP-1 dose without labs?
A physician can adjust your dose based on symptoms and reported response, but without labs they’re working with incomplete information. Standard titration follows the medication’s prescribing schedule by default; clinical adjustments (slowing titration for side effects, accelerating for inadequate response) are stronger when grounded in lab data.
What happens if my labs show something unexpected?
Your physician interprets the labs in the context of your overall clinical picture. Some changes are expected and reflect therapy working (HbA1c dropping, lipid panel improving). Some warrant adjustment (persistent kidney function changes, thyroid abnormalities, pancreatic enzyme elevation). Your physician will discuss findings with you and recommend next steps.
Medical review: This article has been reviewed by board-certified physicians within Elara’s telehealth provider network. Last reviewed: May 2026.
Compounded semaglutide and tirzepatide are prepared by state-licensed 503A compounding pharmacies under state pharmacy board oversight, pursuant to patient-specific prescriptions issued by board-certified physicians. These medications are not FDA-approved as finished drug products. GLP-1 medications are contraindicated in patients with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN2). Lab reference ranges may vary by laboratory; your physician will interpret your specific values in clinical context. Results vary and are not guaranteed. This content is for informational purposes only and is not a substitute for professional medical advice. Consult your physician before starting or changing any treatment.