- Get a full baseline panel before your first dose, so you can see what actually changes.
- Recheck at about 3, 6 and 12 months. Metabolic markers usually improve; kidney and hydration markers need watching.
- The scale shows weight. Your labs show whether you're losing fat, keeping muscle and staying nourished.
GLP-1 medications like semaglutide and tirzepatide can change your metabolism fast. Bloodwork is how you and your prescriber see whether those changes are healthy, and when something needs adjusting.
Insyght's panel covers the metabolic, liver, kidney and nutrient markers that matter on treatment, reviewed by a physician. $199 a year.
Your GLP-1 lab checklist
- Blood sugar: Hemoglobin A1c, fasting glucose, fasting insulin
- Heart: full lipid panel, ApoB, triglyceride/HDL ratio
- Liver and gallbladder: ALT, AST, GGT, alkaline phosphatase, bilirubin
- Kidneys and hydration: creatinine, eGFR, BUN, sodium, potassium
- Nutrition and muscle: albumin, total protein, ferritin, vitamin D, CBC
- Thyroid: TSH, Free T4
- Inflammation: hs-CRP
Insyght's Core Panel covers every item on this list.
When to test
| When | Why | Focus on |
|---|---|---|
| Before your first dose | Sets your starting point | The full checklist |
| 3 months | Catches early side effects | Kidney and hydration markers, liver enzymes, electrolytes |
| 6 months | Shows real metabolic change | A1C, fasting insulin, lipids, ApoB, albumin, ferritin |
| 12 months | Confirms long-term progress | The full checklist |
| 3 months after stopping | Shows what holds | A1C, fasting insulin, lipids, weight trend |
What changes to expect
| Marker | Common direction on treatment | What it means |
|---|---|---|
| A1C and fasting glucose | ↓ | Better blood sugar control |
| Fasting insulin | ↓ | Improved insulin sensitivity |
| Triglycerides | ↓ | Less fat made and stored by the liver |
| ALT and GGT | Often ↓ | Fatty liver may be improving |
| BUN and sodium | Can ↑ | You may be drinking too little |
| Albumin, ferritin, vitamin D | Can ↓ | Eating less may leave gaps in protein or nutrients |
These are typical patterns, not guarantees. Your prescriber will read your results against your own baseline.
Protecting muscle while you lose weight
A meaningful share of weight lost on GLP-1s can come from lean mass. No single blood test measures muscle directly. Albumin, total protein and creatinine trends, along with strength and body composition checks, help your care team spot a problem early. Prioritize protein at every meal and add strength training two to three times a week.
Red flags to act on quickly
Seek care quickly for severe or constant belly pain (especially spreading to the back), pain under the right ribs, vomiting that won't stop, very dark urine or signs of dehydration. These can signal pancreatitis, gallbladder problems or kidney strain.
Staying hydrated matters more than usual on these medications. Sip water steadily through the day, even when you don't feel thirsty.
Frequently asked questions
What labs should I get before starting a GLP-1?
How often should I get bloodwork on a GLP-1?
Why do my kidney numbers look worse on a GLP-1?
Insyght tests 100+ biomarkers in one draw, so you and your prescriber can see what's really changing. $199 a year, no insurance needed.
Keep reading
How we read 100+ biomarkers against optimal, not just the population average.
The panelWhat we testEvery biomarker in the Insyght Core Panel, across 10 body systems.
60 secondsThe Baseline CheckEight questions to see which of your systems deserves a closer look.
