Laboratory Testing Before Initiating GLP-1 Receptor Agonists

Essential Laboratory Tests

The American College of Cardiology recommends obtaining renal function tests, including serum creatinine and estimated glomerular filtration rate (eGFR), before starting a GLP-1 receptor agonist, as these medications have different dosing requirements and contraindications based on kidney function 1
The American Diabetes Association suggests measuring baseline HbA1c to establish baseline glycemic control and guide treatment expectations, with higher baseline HbA1c associated with increased treatment failure risk (odds ratio 1.3 per one unit increase) 4, 5
The American College of Cardiology recommends assessing baseline cardiovascular risk with a lipid panel, particularly important for GLP-1 receptor agonists with proven cardiovascular benefit (liraglutide, semaglutide) 2, 4
The Endocrine Society recommends establishing baseline hepatic status with liver function tests (ALT, AST, bilirubin), as GLP-1 receptor agonists are metabolized through proteolytic degradation and some patients may have non-alcoholic fatty liver disease associated with obesity or diabetes 1

The American College of Cardiology suggests measuring amylase and lipase if the patient has any history of pancreatitis, as this is a contraindication to GLP-1 receptor agonist therapy, and these medications should be discontinued if pancreatitis is suspected and never restarted if confirmed 2, 3
The American Thyroid Association recommends considering thyroid function tests if there is personal or family history of thyroid disease, as personal or family history of medullary thyroid cancer or multiple endocrine neoplasia syndrome type 2 (MEN2) are absolute contraindications 2

The American College of Cardiology recommends monitoring eGFR when initiating or escalating doses of liraglutide and semaglutide, especially in patients with adverse gastrointestinal reactions, and re-checking eGFR during dose escalation if the patient develops severe gastrointestinal adverse effects 1, 3
The American Diabetes Association suggests monitoring for hypoglycemia risk if the patient is on concurrent insulin or sulfonylureas, as dose reduction of these agents may be required 2, 3
The American Academy of Ophthalmology recommends baseline retinal assessment for patients with diabetic retinopathy, as semaglutide has been associated with diabetic retinopathy complications, potentially related to rapid glucose reduction 2