Get a CGM prescription — see what your blood sugar actually does

A continuous glucose monitor is a small sensor — about the size of a quarter, with a thin filament that sits in the interstitial fluid just below the skin — that reports your blood sugar every 1-5 minutes for 10-14 days at a time. The data streams to your phone. You see your levels in real time, your meal responses, your overnight patterns, and the cumulative graph that tells the story of your metabolic day.

For people with diabetes, CGMs revolutionized care. For non-diabetics in metabolic optimization, they've opened up a different kind of insight. The same meal — a bowl of oatmeal, a slice of bread, a serving of pasta — can cause one person's glucose to spike to 180 and another's to barely move. Stress, sleep quality, what you ate yesterday, the time of day, and what you do after eating all change the response. A CGM lets you see these patterns in your own body, in your own life, with your own foods.

Within a few weeks of wearing one, most members significantly change how they eat — not because of a diet rule but because they can see directly what their body does. That kind of behavior change tends to stick.

The sensor sits in interstitial fluid (the fluid between cells) just below the skin, not directly in the blood. Glucose diffuses from blood into interstitial fluid with a slight lag — typically 5-10 minutes. The sensor uses an enzymatic reaction (glucose oxidase) to measure the glucose concentration and reports it to the transmitter.

Modern CGMs are factory-calibrated and don't require fingerstick calibration. Accuracy is high enough that diabetic insulin dosing is now done directly off CGM readings in most cases. For non-diabetic metabolic insight, the accuracy is more than sufficient.

Two devices dominate the US market: Dexcom G7 and FreeStyle Libre 3. Both are factory-calibrated, last 14 days per sensor, and stream to a smartphone. Dexcom has more frequent updates (every minute); FreeStyle reports every minute as well in newer versions. Either works well for metabolic insight; your clinician can discuss which fits.

The data reveals patterns most people never see: how a "healthy" breakfast spikes them to 170 while their teenager eats the same thing and barely registers 100; how a stressful meeting raises glucose by 30 points without food; how poor sleep doubles their morning glucose response; how a 10-minute walk after dinner cuts the peak in half.

Schedule a 15-minute telehealth visit. Your clinician confirms a CGM is reasonable for you, reviews any contraindications, and writes the prescription.

The prescription goes to a pharmacy that ships the sensors and transmitter directly to you. Most members start with a 14-day sensor; many continue with monthly or quarterly sensors after the initial experience.

You download the manufacturer's app and follow the simple application instructions — clean the area on the back of your upper arm, attach the sensor with the applicator, wait an hour for it to warm up. Then it streams data to your phone for 14 days.

At day 14 you remove the sensor and apply the next one (if continuing). HealifyNow includes a clinician review visit at 2-4 weeks where you walk through your data together and identify patterns to act on.

Many members wear a CGM for 2-3 months to understand their metabolic patterns, then take a break. Others stay on continuously for the data. Either is reasonable.