Lingo vs Stelo: Which Over-the-Counter CGM Is Better for LADA, Prediabetes, or the Honeymoon Phase?

Disclosure: This post contains Amazon affiliate links. I bought both CGMs myself and am not sponsored by either company. If you buy through these links, I may earn a small commission — at no extra cost to you.

Continuous glucose monitors (CGMs) used to be something you could only get with a prescription — usually after a diabetes diagnosis, and often only if you were already using insulin.

That’s no longer true.

Today, over-the-counter (OTC) CGMs are available in the U.S. for adults who don’t require insulin, and they open up an entirely new way to understand blood sugar before things spiral out of control.

In this article, I’m comparing the Abbott Lingo and the Dexcom Stelo, two OTC CGMs you can buy without a prescription. I tested both of them side-by-side, compared them to my medical-grade CGM and fingerstick blood glucose meter, and evaluated not just accuracy — but how useful they are for people who:

• are questioning whether they might have LADA
• are in the LADA honeymoon phase
• have prediabetes
• or are managing early autoimmune diabetes with diet and exercise

📺 Watch the full video comparison here:

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What Are Over-the-Counter CGMs (and Who Are They For)?

OTC CGMs measure glucose in interstitial fluid (the fluid between cells just under the skin) using a tiny filament inserted just under the skin. They send readings directly to your phone.

They are designed for adults who:

• do not require insulin
• do not need alerts for dangerous low blood sugar
• want insight into how food, exercise, stress, sleep, and hormones affect glucose

They are not a replacement for medical-grade CGMs for people using insulin — and I’ll explain why later.

These tools can help people identify patterns early, make lifestyle changes sooner, and walk into a doctor’s appointment with real data instead of guesswork.

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How I Tested Lingo vs Stelo (Accuracy Matters)

I wanted this comparison to be as objective as possible.

Here’s what I did:

• Wore Lingo and Stelo at the same time
• Compared both to my medical-grade Guardian 4 CGM
• Verified readings using a Contour Next blood glucose meter
• Only compared values during stable glucose periods (to avoid lag issues)

I also compared:

1. OTC CGM vs fingerstick
2. OTC CGM vs medical CGM
3. Graphs and trends across all three apps

Direct Comparison #1

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Direct Comparison #2

Direct Comparison #3

Accuracy Results (MARD Comparison)

All three sensors performed extremely well.

A small amount of variation is normal because CGMs measure interstitial fluid, not blood — and interstitial glucose lags slightly behind blood glucose.

Device	MARD (%)
Guardian 4 (medical CGM)	6.92%
Abbott Lingo	6.36%
Dexcom Stelo	7.87%

Bottom line:

👉 Both Lingo and Stelo are very accurate.

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Abbott Lingo Review: Encouraging, Lifestyle-Focused, Fixed Range

What Lingo Does Well

• Readings every 1 minute (very detailed)
• Strong focus on habits and behavior change
• Positive, encouraging messaging
• Challenges and lifestyle suggestions (sleep, exercise, eating patterns)

Lingo is clearly designed for non-diabetic people who want to improve overall metabolic health.

Screenshots from Lingo App on Android

App is also available for iOS (iPhone).

Limitations That Matter for LADA

• Fixed glucose range: 70–140 mg/dL (cannot be customized)
• Maximum display value: 200 mg/dL
• Uses a proprietary metric called “Lingo Count”
  • I personally found this confusing
  • It’s not used by medical CGMs or clinicians

For someone without diabetes, this may be perfect.

For someone with LADA diabetes, the fixed range can be frustrating — because glucose will naturally exceed that range more often.

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Dexcom Stelo Review: Flexible, Clinical, Diabetes-Aware

Stelo feels fundamentally different — and that difference matters for people with LADA or prediabetes.

What Stelo Does Exceptionally Well

• Uses Time in Range (TIR) — the industry-standard CGM metric
• Fully customizable glucose ranges
• Spike detection + pattern recognition
• Health-goal driven onboarding
• Readings up to 250 mg/dL

Time in Range is the same metric used by:

• endocrinologists
• diabetes researchers
• medical CGMs

That makes Stelo much easier to share with a doctor and integrate into real clinical conversations.

Pictures of Stelo App showing Spike Detection Technology

Tradeoffs

• Updates every 15 minutes (not every minute)
• Must be purchased as a 2-pack

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Lingo vs Stelo: Key Differences at a Glance

Highlights:

• Lingo: minute-by-minute data, fixed healthy range, lifestyle coaching
• Stelo: customizable ranges, Time in Range, better for people with diabetes

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Which OTC CGM Is Better for LADA or Prediabetes?

Here’s my honest take:

• If you are metabolically healthy and curious → Lingo
• If you have prediabetes, early LADA, or rising glucose → Stelo
• If you want data your doctor will immediately understand → Stelo

Both are accurate. Both are well-made.

But Stelo is better aligned with how diabetes is actually managed, especially for people hovering in that early autoimmune phase.

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Important Reminder: OTC CGMs vs Medical CGMs

OTC CGMs:

• do not alert for dangerous lows
• do not integrate with insulin pumps
• are not for insulin dosing decisions

If you use insulin or experience hypoglycemia, you need a medical-grade CGM.

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Where to Buy Lingo and Stelo

You can purchase both OTC CGMs on Amazon:

• 👉 Buy Abbott Lingo on Amazon
• 👉 Buy Dexcom Stelo on Amazon

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Final Thoughts

If you’re questioning whether you might have LADA, navigating the honeymoon phase, or trying to control glucose with lifestyle changes, information is power.

OTC CGMs give you that power — no prescription required!

If you found this helpful:

• watch the above video
• leave a comment with your thoughts (I’ll try to reply to any questions)