RE: Dexcom G6 - Glucose tab response time

Hello everybody,

6 weeks ago I took the plunge and began using the Dexcom G6 CGM. I have been a Type 1 diabetic for 31 years but in the last 3 years have become very physically active and exercise daily. The benefit was the massive weight loss but the downside was loss of control of my glucose levels. I cut my insulin use in half (Novolog and Lantus) but the hypoglycemic reactions could get quite dangerous. The last 6 weeks on the CGM have been amazing. I have learned much about my condition that I never before knew!

One thing I am challenged with is the response time I have to using glucose tablets when my glucose levels go low. I find that it might take 7 minutes before I see my glucose respond. Does anybody know a good resource I could use to learn more about glucose response times for hypoglycemic reactions?


Standard protocol says 15 min until you see the effect of the carb.
With Dexcom (because the readings lag), you might need to wait an additional 15 min to see that value appear on the sensor.

So, if you dose the sugar once, wait 15, then check manual BG to see effect.
Then, rinse and repeat if you need more sugar.

Anything oral will be assumed to take 15 min to get into the blood stream.
That’s just how things are.

Wow, cutting the insulin dose in half is really something.
Exercise is always gonna be a ■■■■■. Its in the nature of the thing, unfortunately.
You might end up on a pump to work efficiently with exercise…when the time is right.

Welcome to the community, Chris.


@Chris77586, welcome. I agree with @mohe0001. The usual is 15 minutes for carbs to hit. I have been on a Dexcom CGM for years, back to the model 7 & 7+ (NO ‘G’ infront of those #s).

I would suggest you check your body’s own response. Pick a time when you are level on the CGM and well away from any meal. Eat 15 grams of carbs, like a rescue (I use the candy SweetTarts - 9 tablets) and time what happens. After you have your data then cover the carbs. Waiting to cover the test dose of carbs will give you both the mouth to CGM time and then the insulin to lowered CGM time.

Please share your findings. Sharing is how we all learn.

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Welcome & congratulations on the CGM usage!

When I first started with Dexcom G4, I was panicked when the numbers were not heading up after eating my glucose tablets. For me with that system it took almost 30 minutes for the system to catch up.

With the G6, I find it pretty accurate throughout the down and back up. But as I am sure you know each of us is an experiment in the making. What works for you, might not work for me. So my suggestion is watch and continue to learn your diabetes. For you, it might take 10 minutes or 20 minutes. It might take 15 minutes in the morning but 25 in the afternoon. The joys of diabetes! But with a CGM you can see everything as it happens. I do find checking my reports every 2 weeks is helpful looking at patterns.

CGM was the best thing that happened to me and my diabetes treatment plan. Blood testing meters were life changing back in the day but this shows me so much more than just what my sugar is at that moment.

Keep asking questions and keep trying new things. You never know what is out there unless you try something new!


Sally, I cannot imagine my life without my CGM. Why on Earth did I wait so long to adopt this technology?!