The standard dose is one tablet, then check your blood sugar 15 minutes later

Most glucose tablets contain 4 to 5 grams of carbohydrate per tablet. One tablet is the starting dose for low blood sugar. After you take it, wait 15 minutes and check your blood sugar again with a meter. If it is still below 70 mg/dL (or whatever your doctor told you), take another tablet and wait another 15 minutes before checking again.

Do not take multiple tablets at once hoping to fix the problem faster. Your body can only absorb so much glucose at a time, and taking too many tablets at once can cause your blood sugar to spike too high an hour or two later, which then requires insulin or other medication to bring back down. The 15-minute wait is the hard part, but it works.

The tablets dissolve quickly on your tongue or you can chew them. Either way, they enter your bloodstream faster than solid food would, which is why they are better than reaching for a candy bar or juice box when you feel shaky.

Key Takeaways

  • Start with one glucose tablet (4 to 5 grams), then wait 15 minutes before checking your blood sugar again.
  • If your blood sugar is still low after 15 minutes, take a second tablet and check again in another 15 minutes.
  • Taking multiple tablets at once does not work faster and often causes your blood sugar to overshoot high later.
  • Keep glucose tablets in your pocket, bag, or car so you have them when you need them, not when you remember to buy them.
  • If you take insulin or certain diabetes medications, your doctor may have given you different instructions for your specific situation.

Why the 15-minute rule matters

Glucose tablets work by raising your blood sugar quickly, but "quickly" does not mean when ready. It takes about 10 to 15 minutes for the glucose to move through your stomach and into your bloodstream enough to show up on a meter. If you take a second tablet after five minutes because you still feel bad, you are actually taking two doses at once, and both will hit your system around the same time.

That double dose can push your blood sugar to 200 or higher, which then makes you feel tired, thirsty, and foggy for hours. You may then take insulin to bring it back down, which can cause another low later. The 15-minute wait breaks that cycle. It feels long when you are shaking, but it prevents the overshoot.

What to do if one tablet is not enough

After 15 minutes, check your blood sugar. If it is 70 mg/dL or above, you are done—eat a snack with protein and fat (like cheese or nuts) within the next hour to keep your blood sugar stable. If it is still below 70, take a second tablet and wait another 15 minutes.

Most lows respond to one or two tablets. If you are taking a third tablet and your blood sugar is still not rising, something else may be wrong—you may have miscounted your insulin dose, eaten less than you thought, or exercised harder than planned. Call your doctor or diabetes educator to talk through what happened. Do not just keep taking tablets and hope it works.

Carrying glucose tablets so you actually have them

Glucose tablets only help if you have them with you. Keep a small container in your pocket, your work bag, your car, and your nightstand. Buy the small packs (usually 3 to 4 tablets per pack) so you can stash them everywhere without thinking about it. Check them every few months—they do not expire quickly, but they can get stale or stick together if they get wet.

Tell the people around you where your tablets are. If you pass out or cannot reach them, someone else needs to know to grab them from your desk drawer or your gym bag. Glucose tablets work only if you can get to them.

When glucose tablets are the wrong choice

Glucose tablets are for low blood sugar when you are conscious and able to swallow. If you are confused, slurring your words, or losing consciousness, you need glucagon—an injection that raises blood sugar fast. Glucagon comes as a kit (GlucaGon, Gvoke, or Baqsimi) that a family member, coworker, or paramedic can use. You cannot give it to yourself if you are not thinking clearly.

If you take a medication like metformin or a GLP-1 drug (like Ozempic or Mounjaro) but not insulin, low blood sugar is rare. Talk to your doctor before carrying glucose tablets, because taking them when your blood sugar is actually normal can cause problems. Your doctor can tell you whether you need them at all.

Storing and checking the expiration date

Glucose tablets stay good for years if you keep them dry and cool. Heat and humidity break them down faster, so do not leave them in a hot car for weeks or in a bathroom where steam from the shower reaches them. A bedroom drawer or a desk drawer at room temperature is fine.

Check the expiration date when you buy them and write it on the container with a marker. Expired tablets may not raise your blood sugar as fast or as much as fresh ones. If your tablets are expired, replace them. They are cheap insurance.

Frequently Asked Questions

Can I take glucose tablets if I am not diabetic?

Glucose tablets are made for people with diabetes or other conditions that cause low blood sugar. If you do not have diabetes and take glucose tablets when your blood sugar is normal, you can cause your blood sugar to spike and then crash, which makes you feel worse. If you feel shaky or dizzy, see a doctor instead of self-treating with glucose.

What if I choke on a glucose tablet?

Glucose tablets are small and dissolve quickly, so choking is rare. If you are worried about choking, you can crush the tablet between your teeth or let it dissolve on your tongue instead of swallowing it whole. Glucose gel or juice are also options if tablets feel unsafe for you.

Do glucose tablets work the same as juice or candy?

Glucose tablets, juice, and regular candy all raise blood sugar, but tablets work faster and more predictably because they are pure glucose. Juice takes 10 to 20 minutes, and candy with fat or fiber takes even longer. Tablets are the standard because you know exactly how much carbohydrate you are getting and when it will hit your system.

Can I take more tablets to prevent a low later?

No. Taking extra tablets when your blood sugar is normal does not prevent a low—it just raises your blood sugar now, which may cause a low later when your insulin catches up. The only way to prevent lows is to eat on schedule, count your carbohydrates correctly, and adjust your insulin dose with your doctor's help.

What should I do if I take too many glucose tablets by accident?

Check your blood sugar in 15 minutes. If it is very high (over 250 mg/dL), you may need to take insulin or wait it out, depending on what your doctor told you to do. Call your diabetes educator or doctor if you are not sure. Do not panic—high blood sugar from glucose tablets is temporary and not dangerous the way a severe low is.