FreeStyle Libre Rio

The FreeStyle Libre Rio is Abbott's first over-the-counter (OTC) continuous glucose monitor (CGM) in the United States — you can buy it without a prescription. It is a small, factory-calibrated sensor worn on the back of the upper arm that measures glucose in the fluid just under the skin and shows readings on a reader or a compatible smartphone app.¹ We include it here for completeness of the OTC CGM category — but read the warnings below: it is not designed for, or indicated for, people with type 1 diabetes.²

Who it's for. The FDA cleared the Libre Rio in June 2024 (510(k) K233861) for adults aged 18 and older with type 2 diabetes who do not use insulin and who typically manage with lifestyle.¹³ That indication is the whole point of the product, and it excludes T1D.

How it works and accuracy. The Rio is built on Abbott's familiar Libre platform — the same form factor as the Libre 2 — with a one-hour warm-up and no fingerstick calibration.²⁴ Abbott has not published a Rio-specific accuracy study, so any MARD figure for it is an inference. The underlying 15-day Libre sensor posted an overall MARD of about 8.2% in adults (and held up in the low range, with ~97% of results within 15 mg/dL of the lab reference during hypoglycemia) in its pivotal study — but that study validated the prescription Libre 2 Plus / 3 Plus, not the Rio.⁵ We score the Rio's accuracy conservatively for that reason and flag the gap honestly.

Wear, range, alerts. The sensor is worn for up to 15 days, and its glucose measuring range is 40-400 mg/dL — wide enough to register very low or very high readings, which Abbott highlights as a first for an OTC CGM.¹ Critically, the Rio has no glucose alarms: it is built for retrospective trend and lifestyle insight, not for real-time low/high warnings.⁴ For someone with T1D, the absence of a low-glucose alarm alone makes it the wrong tool.

What it works with. Effectively nothing in the T1D stack. The Rio does not drive any automated insulin delivery (AID) system, does not integrate with pumps, and is not intended for insulin users or DIY loops.⁴ This is a deliberate, closed consumer design — the opposite of Abbott's iCGM-classed Libre 2 Plus and 3 Plus, which are cleared to power Tandem and Omnipod systems. It has no ketone sensing.¹

Access and cost. The Libre Rio is US-only and sold over the counter, so it is paid out of pocket — standard insurance and Medicare generally do not cover OTC CGMs. Abbott's wellness sibling Lingo launched in the US in September 2024 at low-cost consumer pricing, and the Rio's OTC pricing sits in the same affordable consumer band.⁶ Its rollout has been gradual; availability lags the headline clearance.

What's coming. The bigger Abbott story for people with T1D is not the Rio but the iCGM Libre line (Libre 2 Plus / 3 Plus, which drive AID) and the upcoming dual glucose-ketone sensor — both tracked separately on this site. The OTC Rio matters mainly as a sign of where consumer glucose sensing is heading: prescription-free, lifestyle-framed, and aimed at the very large type-2 and wellness market rather than at intensive insulin users.²

References

1. Abbott. Abbott Receives U.S. FDA Clearance for Two New Over-the-Counter Continuous Glucose Monitoring Systems (Libre Rio: OTC iCGM, adults 18+ with type 2 not on insulin; range 40-400 mg/dL; up to 15-day wear; reader or smartphone app). PR Newswire / Abbott (June 10, 2024). https://www.prnewswire.com/news-releases/abbott-receives-us-fda-clearance-for-two-new-over-the-counter-continuous-glucose-monitoring-systems-302167780.html ↩ ↩² ↩³ ↩⁴

2. Abbott. Abbott Launches Lingo & Libre Rio in U.S. Biowearables Market (Libre Rio is an OTC iCGM for people with diabetes — type 2, non-insulin; Lingo is a wellness product). Abbott Newsroom (2024). https://www.abbott.com/en-us/corpnewsroom/strategy-and-strength/abbott-enters-us-consumer-biowearables-market-with-lingo-and-libre-rio ↩ ↩² ↩³

3. U.S. FDA. Libre Rio — 510(k) Premarket Notification K233861 (Abbott Diabetes Care). FDA 510(k) Database (2024). https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K233861 ↩

4. CGM Monitors. FDA-Approved Over-the-Counter Libre Rio — Features and More (no glucose alarms — trend/lifestyle insight only; calibration-free, one-hour warm-up; smartphone app; not for insulin users or AID systems; same small sensor as Libre 2). CGMmonitors.com (2024). https://cgmmonitors.com/fda-approved-over-the-counter-libre-rio/ ↩ ↩² ↩³

5. Alva S, Bhargava A, Bode B, et al. Accuracy of a 15-day Factory-Calibrated Continuous Glucose Monitoring System With Improved Sensor Design (8.2% adult MARD; 97% of hypo results within 15 mg/dL; validates the prescription Libre 2 Plus / 3 Plus platform, not the Rio specifically). J Diabetes Sci Technol (2025). doi:10.1177/19322968251329364 (PMID 40183340). https://pmc.ncbi.nlm.nih.gov/articles/PMC11977615/ ↩

6. Tirrell M. Abbott debuts Lingo over-the-counter CGM in the US (Lingo launched Sept 2024 at low-cost consumer pricing; Libre Rio for people with diabetes to follow at consumer pricing). MedTech Dive (September 2024). https://www.medtechdive.com/news/abbott-lingo-rollout-us-otc-cgm/726330/ ↩