Comprehensive metabolic panel (CMP): the 14 tests, their common ranges, and what each one is doing on a GLP-1 baseline

If a prescriber orders one tube before a GLP-1 prescription, it is this one. The comprehensive metabolic panel is fourteen tests run together on a single sample, and between them they cover glucose, kidney function, fluid and electrolyte balance, liver enzymes and blood proteins. It is the baseline against which the labels' one explicit re-check instruction is measured.

The fourteen results and the MedlinePlus ranges

Most reports also print an estimated GFR calculated from the creatinine, age and sex. It is not a separate test but it is the number kidney decisions are made on; the kidney function page covers it.

Why it is the standard baseline

The labels' one explicit re-check is a CMP test. Each of the Wegovy, Ozempic, Zepbound and Mounjaro labels carries a warning about acute kidney injury due to volume depletion. The Wegovy label says there have been postmarketing reports of acute kidney injury, in some cases requiring hemodialysis, that most occurred in people who had gastrointestinal reactions leading to dehydration, and instructs prescribers to monitor renal function in patients reporting reactions that could lead to volume depletion, especially during initiation and escalation. Renal function means creatinine and eGFR, with the electrolytes alongside. A baseline is what makes a re-check interpretable.

It is the ADA's initial evaluation. For people with diabetes, the Standards of Care list serum creatinine with eGFR, potassium (for people on ACE inhibitors, ARBs or diuretics) and liver function tests among the labs of a comprehensive medical evaluation.

It catches the things that change the plan. A low eGFR, a high ALT, a low sodium: any of these before the first dose sends the prescriber down a different path than the same finding discovered at week eight, when it is hard to know whether the drug, the weight loss or a pre-existing condition explains it.

How often it is repeated

No label sets an interval for a routine CMP. In practice: a baseline before starting; a repeat when the labels' trigger fires (vomiting, diarrhea, poor fluid intake, dizziness on standing); and then with the annual review. People with kidney disease, liver disease or diabetes follow their own schedules, which the kidney and liver pages cover. Repeating a CMP every month in someone who feels well is not something any label or guideline asks for.

Reading the panel as a whole

The clinician does not read fourteen numbers separately. A few patterns matter more than any single flag.

• BUN up, creatinine up, CO2 down, sodium up: the picture of someone who has been dry. On GLP-1 therapy during a run of nausea, this is the pattern the labels are asking prescribers to catch.
• ALT above AST, both mildly raised, everything else normal: common in fatty liver, and the pattern that often improves with weight loss.
• Calcium low with albumin low: often not a calcium problem at all; calcium travels bound to albumin and a "corrected" calcium is calculated.
• Glucose high on a non-fasting sample: means little until it is repeated fasting.

What to discuss with your prescriber

• Whether to fast for the baseline draw.
• Which of the fourteen numbers your prescriber will watch, given your history and medicines.
• What symptoms should prompt an early re-check (the dehydration trigger from the labels), and how to reach the practice when they happen.
• Whether a BMP is enough for that re-check, so you know what is being ordered.

For the arithmetic side of therapy, dose conversions and schedules, the FormBlends calculators are the network's tool site. To keep your own CMP results in one place, use the lab tracker.