SugarMD - Dexcom G6 vs Freestyle Libre - Endocrinologist review and comparison [2020]

Short Summary

Main recommendation: For patients who have frequent lows or fear of lows, the endocrinologist recommends the Dexcom G6 over FreeStyle Libre, mainly because it is more accurate in the low range and has stronger alarms; FreeStyle Libre is considered acceptable for patients who mainly want to avoid finger sticks and are satisfied with it. The speaker frames the choice as depending on accuracy needs, cost, insurance coverage, and what matters most to the patient.

Key Points

• Dexcom and FreeStyle Libre do not measure blood sugar directly, so their readings will not match a finger stick exactly, especially when glucose is changing quickly.
• The speaker says the most useful feature is the trend data and arrows, which indicate where glucose is heading, rather than the exact number.
• The Dexcom G6 is more reliable below about 80 or 70 mg/dL; the speaker does not rely on FreeStyle Libre readings in the very low range.
• Dexcom's alarms sound even on silent for lows at or below 55 and include a predictive alert for a drop to 55 within about 20 minutes, which the speaker says is accurate 85 to 90 percent of the time.
• Sensor life differs: FreeStyle Libre is rated for 14 days and Dexcom for 10 days, but the speaker says only about 80% of FreeStyle Libre sensors reach 14 days per the company's own data, and reports frequent early failures, while Dexcom failures are uncommon in his experience.
• Insurance can make switching hard: if a patient starts with FreeStyle Libre and then wants Dexcom, insurers may resist because the patient already has a sensor.

Details Worth Noting

• Concrete instructions: Do not compare a finger stick directly to the CGM number; if readings are changing rapidly, focus on the arrow direction and expect a delay. If your sugar is 100 with two down arrows, the speaker says it could drop low within 20 to 30 minutes, so act on it. Check a finger stick when the device says to, or when symptoms such as shakiness or sweating do not match the reading. If you have recurring lows at the same time of day, talk to your doctor so your insulin or medication can be adjusted.
• The speaker says a Dexcom reading of 60 may mean the true value is anywhere from 50 to 65, while a FreeStyle Libre reading may be far off in either direction at low levels.
• If you fail a FreeStyle Libre sensor early, call the company; the speaker says they may replace it, and that patients paying for a sensor should be compensated or get a replacement quickly (he notes he does not speak for the company and policies may change).
• Medicare covers both systems for patients on three or more daily injections, but Medicare patients typically pay 20 percent of the cost, and Dexcom is more expensive.
• Other options mentioned: Medtronic Guardian works with the 670G pump in a closed-loop system but requires calibration at least twice daily and has many false alarms, according to the speaker. Eversense is placed surgically in a short office procedure every three months, has a removable transmitter, and avoids the adhesive rash problem; the speaker notes about 10 percent of people cannot tolerate the adhesive used by Dexcom and Libre.

Bottom Line For frequent lows, the Dexcom G6 is the stronger choice, while FreeStyle Libre suits patients who mainly want fewer finger sticks and accept less precision at low glucose levels.