The best CGM depends on how you manage your diabetes, what devices you already use, and how much you want to spend. For most people with insulin-dependent diabetes, the Dexcom G7 offers the strongest combination of accuracy, smartphone alerts, and insulin pump compatibility. The FreeStyle Libre 3 is a close competitor at a lower price point, and several other options fill specific niches worth knowing about.
Dexcom G7: The Most Connected Option
The Dexcom G7 is the go-to choice for people who want their CGM to talk to other devices. It integrates directly with the Tandem t:slim X2 insulin pump using Control-IQ technology, creating a semi-automated system that adjusts insulin delivery based on real-time glucose data. Omnipod 5 also pairs with Dexcom sensors. If you use or plan to use an insulin pump, this compatibility alone can be the deciding factor.
Beyond pump integration, the G7 sends continuous readings to your smartphone and can relay data to compatible Garmin smartwatches and Apple devices, though your phone needs to stay in Bluetooth range of both the sensor and the watch. The system provides customizable high and low glucose alerts, trend arrows showing which direction your levels are heading, and shareable reports for your care team.
Cost is the G7’s main drawback. Without insurance, Dexcom offers a pharmacy savings program at $89 per month, but the full retail price runs significantly higher. With commercial insurance, coverage varies widely by plan.
FreeStyle Libre 3: Best Value for Prescription CGM
Abbott’s FreeStyle Libre 3 delivers many of the same core features as the Dexcom G7 at a lower cost. Most commercially insured patients pay between $0 and $75 per month for sensors, making it the more affordable prescription option for the majority of users. Each sensor lasts 14 days, and like the G7, it sends continuous readings to your phone without finger pricks or scanning.
The Libre 3 includes optional alerts for high and low glucose and displays trend arrows. Where it falls short compared to Dexcom is in device integration. As of early 2025, the Libre 3 does not connect to the Tandem t:slim X2 or Medtronic pumps, though an updated version (the Libre 3+) is expected to gain Tandem compatibility. If you don’t use an insulin pump and want reliable glucose data at the lowest monthly cost, the Libre 3 is hard to beat.
Eversense E3: The Implantable Alternative
The Eversense E3 takes a completely different approach. Instead of a disposable sensor you stick on your skin every week or two, a healthcare provider inserts a small sensor under your skin that lasts up to 180 days. That’s six months between sensor changes. A removable transmitter worn on top of the skin over the implant site picks up the signal and sends it to your phone.
The insertion is a minor in-office procedure. A provider creates a small pocket under the skin using specialized tools and slides the sensor in. Removal at the end of six months is a similar office visit. This system is FDA-approved for adults 18 and older with diabetes. It appeals to people who find frequent sensor changes annoying, who have skin irritation from adhesives, or who simply want the longest-lasting option available. The tradeoff is that you need a clinic visit twice a year for sensor swaps, and the Eversense does not currently integrate with any insulin pumps.
Medtronic Guardian 4: Best for Medtronic Pump Users
If you use the Medtronic MiniMed 780G insulin pump with SmartGuard technology, the Guardian 4 sensor is your only compatible CGM. It does not work with Tandem or Omnipod systems, and neither Dexcom nor Libre sensors work with Medtronic pumps. This is a locked ecosystem: your pump choice dictates your CGM, and vice versa. The Guardian 4 is a solid sensor within that system, but it’s not a competitive option for anyone using a different pump or no pump at all.
Over-the-Counter CGMs for Non-Insulin Users
Two newer CGMs target people who don’t take insulin, including those with type 2 diabetes managed through diet and oral medications, or even people without diabetes who want to understand how food affects their blood sugar.
The FreeStyle Lingo is FDA-approved for people 18 and older who are not on insulin. Each sensor lasts 14 days, and pricing runs $49 for a single sensor, $89 for two, or $249 for six. It includes optional glucose alerts and trend arrows, giving it more functionality than its competitor in this space.
The Dexcom Stelo is approved for adults with type 2 diabetes who don’t use insulin. Its sensor lasts up to 15 days. The Stelo is more limited on alerts: it’s designed primarily to help you see how meals and activity affect your blood sugar rather than to warn you about dangerous highs or lows. Both devices are small, all-in-one sensor-transmitters that send readings to a smartphone app with no finger pricks required.
If you want an OTC CGM with more active glucose monitoring features, the Lingo currently offers more. If you’re mainly curious about food responses and want a passive tracking experience, the Stelo fits that use case.
How to Choose the Right CGM
Your decision comes down to a few practical questions:
- Do you use an insulin pump? Check compatibility first. Dexcom G7 works with Tandem and Omnipod. Guardian 4 works only with Medtronic. If your pump and CGM don’t talk to each other, you lose the biggest benefit of wearing both.
- Is cost your top concern? The FreeStyle Libre 3 consistently comes in at the lowest monthly price for insured patients. For uninsured users, Dexcom’s $89/month pharmacy program narrows the gap but doesn’t close it entirely.
- Do you hate changing sensors? The Eversense E3 lasts six months. Everything else needs replacing every 10 to 15 days.
- Are you not on insulin? The Lingo and Stelo are available without a prescription and designed for people managing blood sugar through lifestyle changes or oral medications.
No single CGM is universally “the best.” The Dexcom G7 wins on connectivity and pump integration. The Libre 3 wins on price. The Eversense wins on longevity. And the OTC options open up glucose monitoring to people who previously had no reason to wear a sensor. Start with what matters most to your daily routine, and the right choice usually becomes obvious.