Independent. Not affiliated with Eli Lilly or Novo Nordisk.Not medical advice. Your prescriber decides your treatment.
GLP-1 Field GuidePractical help, sourced from the label

Do you need a glucose monitor on a GLP-1?

Most people taking Zepbound or Wegovy for weight do not need one. Here is who should ask their prescriber, what over-the-counter monitors are cleared for, and what the research says about weight.

Compiled by the GLP-1 Field Guide editorUpdated 5 min readSourced from official labels. Not yet clinically reviewed.
Key points
  • Low blood sugar is more likely with insulin or a sulfonylurea, the labels say. If you take either, ask your prescriber about monitoring.
  • Over-the-counter monitors need no prescription, but are cleared only for adults not using insulin.
  • Reviews find no clear weight benefit from a monitor on its own.
  • If you want the data, it seems to work best as part of a structured program.

Who it suits, at a glance

Not requiredGLP-1 for weight, no diabetes
  • The labels' low blood sugar warnings focus on insulin and sulfonylureas
  • Reviews find no clear weight benefit from a monitor alone
Talk to your prescriberDiabetes, insulin or a sulfonylurea
  • Low blood sugar is more likely
  • Those doses may need lowering
  • Over-the-counter monitors are not for insulin users
Optional extraYou want to see how food affects you
  • Over-the-counter monitors need no prescription
  • Seems to help most within a structured program
  • Prediabetes showed the clearest benefit
Who a continuous glucose monitor suits when you take a GLP-1. Sources are in the text below.

GLP-1s and low blood sugar

The Zepbound label says people taking it with a sulfonylurea (a type of diabetes pill) had a higher risk of low blood sugar, and that the risk is also higher with insulin. It says lowering the insulin or sulfonylurea dose may reduce that risk, and that patients should be taught the signs.[1] The Wegovy label also warns of a higher risk with insulin, and says low blood sugar has been reported with GLP-1 medicines in adults without type 2 diabetes.[2]

So if you have diabetes and take insulin or a sulfonylurea, ask your prescriber how you should check your blood sugar. That decision, and any change to those doses, is theirs to make. See our warning signs guidefor when to call them.

Over-the-counter monitors

A continuous glucose monitor (CGM) is a small sensor worn on the skin that reads your glucose through the day and sends it to a phone app. In March 2024 the FDA cleared the first one you can buy without a prescription, Dexcom Stelo. The FDA says it is for adults 18 and older who do not use insulin, including people without diabetes who want to see how diet and exercise affect their blood sugar. It is not for people with problematic low blood sugar, because it cannot alert them. Each sensor lasts up to 15 days and shows a reading every 15 minutes.[3]

The FDA also says not to make medical decisions from the readings without talking to your healthcare provider.[3]

What the research shows

A 2026 review pooled 23 studies of 1,074 people without diabetes. Using a monitor improved average blood sugar but made no significant difference to BMI. The clearest benefit was in people with prediabetes, with no noticeable benefit in people with normal blood sugar. The authors concluded a monitor is unlikely to help with weight on its own, and works best as feedback within a structured lifestyle program.[5]

An earlier review of 25 trials, mostly in people with diabetes, found small improvements in blood sugar control but no significant effect on weight or BMI.[6] Neither review looked specifically at people taking a GLP-1.

If you want to try one

If you do not use insulin and want to see how meals affect you, an over-the-counter monitor is an option. The research above suggests pairing it with a plan for what to change, rather than using the numbers alone.

Common questions

Do I need a glucose monitor on Zepbound or Wegovy?

Not usually, if you are taking it for weight and do not have diabetes. The labels warn that low blood sugar is more likely when these medicines are used with insulin or a sulfonylurea, so if you take either of those, ask your prescriber how to monitor.

Can a GLP-1 cause low blood sugar if I do not have diabetes?

It is uncommon, but the Wegovy label says episodes of low blood sugar have been reported with GLP-1 medicines in adults without type 2 diabetes. The risk is higher when they are taken with insulin or a sulfonylurea.

Do I need a prescription for a continuous glucose monitor?

Not for an over-the-counter one. The FDA cleared the first over-the-counter monitor, Dexcom Stelo, in March 2024 for adults 18 and older who do not use insulin. It is not meant for people with problematic low blood sugar.

Will a glucose monitor help me lose more weight?

The research so far does not show that. A 2026 review of 23 studies in people without diabetes found no significant difference in BMI, and concluded a monitor is unlikely to help with weight on its own, without a structured lifestyle program.

Not medical adviceThis guide explains what the official instructions say. Your prescriber and pharmacist know your situation, so ask them if anything here does not match what you were told.

Sources

  1. Eli Lilly and Company. Zepbound (tirzepatide) Prescribing Information. Revised 08/2026. Last checked 2026-10-01.
  2. Novo Nordisk. Wegovy (semaglutide) Prescribing Information. Revised 06/2026. Last checked 2026-10-01.
  3. US Food and Drug Administration (press announcement). FDA clears first over-the-counter continuous glucose monitor. Revised March 5, 2024. Last checked 2026-10-22.
  4. US Food and Drug Administration (510(k) database). Signos Glucose Monitoring System, 510(k) K250106. Revised Decision March 21, 2025. Last checked 2026-10-22.
  5. European Journal of Medical Research (peer-reviewed). Continuous glucose monitoring in non-diabetic populations: a systematic review of observational and interventional studies with meta-analysis (Liao et al., European Journal of Medical Research). Revised January 26, 2026. Last checked 2026-10-22.
  6. International Journal of Behavioral Nutrition and Physical Activity (peer-reviewed, via PMC). The efficacy of using continuous glucose monitoring as a behaviour change tool in populations with and without diabetes: a systematic review and meta-analysis of randomised controlled trials (Richardson et al.). Revised December 23, 2024. Last checked 2026-10-22.
  7. Signos. Signos: continuous glucose monitoring for weight management. Revised n/a (web page). Last checked 2026-10-22.
Common side effectsWhat the labels say, and what helps.Warning signsWhen to call your prescriber.GLP-1 eligibility checkerSee what the labels cover for you.Injection logbookTrack sites and doses.