The fastest way to raise blood sugar is to eat or drink 15 grams of simple carbohydrates, such as 4 ounces of fruit juice, regular soda, or glucose tablets. Most people feel better within 15 minutes. What you choose and how much you consume matters, though, because the wrong approach can send blood sugar swinging too far in the other direction.
Recognizing Low Blood Sugar
Before reaching for something sugary, it helps to know what low blood sugar actually feels like. Early signs include shakiness, sweating, a fast heartbeat, dizziness, and sudden intense hunger. You may also feel irritable, anxious, or have trouble concentrating. Some people notice tingling or numbness in their lips or cheeks.
If blood sugar continues to drop, symptoms get more serious: confusion, slurred speech, blurry vision, and loss of coordination. Severe episodes can lead to seizures or loss of consciousness. Catching it early, when you’re still alert enough to eat or drink, makes treatment straightforward.
The 15-15 Rule
The CDC recommends a simple method called the 15-15 rule: consume 15 grams of fast-acting carbohydrates, wait 15 minutes, then check your blood sugar again. If it’s still low, repeat with another 15 grams. This measured approach prevents you from overcorrecting.
Good sources of roughly 15 grams of fast-acting carbs include:
- Glucose tablets: 3 to 4 tablets, depending on the brand (check the label)
- Fruit juice: about 4 ounces (half a cup)
- Regular soda: about 4 ounces (not diet)
- Hard candies: a small handful, typically 4 to 5 pieces
- Table sugar or honey: about 1 tablespoon
Glucose tablets are often the most reliable option because they’re pre-measured and portable. Juice and regular soda work well too, but it’s easy to drink more than 4 ounces when you’re shaky and anxious, which leads to overcorrection.
Why Simple Carbs Work Fastest
Simple carbohydrates are small sugar molecules your body absorbs almost immediately. They enter the bloodstream quickly because there’s very little digestion required. That’s why juice, candy, and glucose tablets raise blood sugar within minutes.
Complex carbohydrates, found in foods like whole grains, beans, and vegetables, take much longer to break down. They contain fiber and larger starch molecules that slow digestion. These are better for sustained energy, but they won’t help during an acute low because they simply don’t act fast enough.
Following Up With a Balanced Snack
Once your blood sugar is back in a safe range, the quick sugar you consumed will burn off rapidly. Without a follow-up snack, you may drop again within an hour or two. Eating something that combines carbohydrates with protein or fat helps keep levels stable. Peanut butter on crackers, cheese with a piece of fruit, or a handful of nuts with a granola bar are all practical options.
Protein and fat slow down the digestion of carbohydrates and delay their absorption into the blood. This prevents the sharp spike-and-crash cycle that can happen when you eat simple sugars alone. Think of the fast-acting carbs as the rescue and the balanced snack as the safety net.
The Risk of Overcorrecting
When blood sugar drops, the instinct is to eat everything in sight. That’s partly biological: your brain is signaling an emergency. But consuming too many carbohydrates during a low can cause rebound hyperglycemia, where blood sugar shoots well above your target range. Diabetes Canada clinical guidelines specifically warn against overtreatment for this reason.
The 15-15 rule exists to counter this instinct. Sticking to 15 grams and waiting, even when it feels painfully slow, gives your body time to absorb the sugar and lets you gauge whether you actually need more. Keeping glucose tablets by your bed or in your bag makes it easier to consume a measured amount rather than raiding the pantry.
Emergency Situations
If someone with low blood sugar is unconscious, having a seizure, or unable to swallow, they cannot safely eat or drink anything. This is when emergency glucagon is needed. Glucagon is a hormone that signals the liver to release its stored sugar into the bloodstream, raising blood sugar rapidly.
Glucagon comes in several forms. Nasal spray versions require no injection and work by spraying powder into the nostril, even if the person is unconscious. Auto-injector pens work similarly to an EpiPen, with a pre-filled dose that’s simple to administer. Traditional glucagon kits require mixing a powder with liquid before injecting, which can be more complicated under stress. All of these are prescription products, and anyone at risk for severe lows should have one on hand and make sure the people around them know where it is and how to use it.
Most glucagon products raise blood sugar within about 10 to 15 minutes. Once the person regains consciousness and can swallow safely, they should eat a snack to replenish the sugar stores the glucagon just emptied from the liver.
Everyday Habits That Help Prevent Lows
Frequent low blood sugar episodes usually point to a pattern worth addressing. Skipping meals, exercising more than usual without adjusting food intake, or drinking alcohol on an empty stomach are common triggers. If you take insulin or certain diabetes medications, the timing and dose relative to meals plays a major role.
Building meals around a combination of carbohydrates, protein, and healthy fat helps keep blood sugar steady throughout the day. Eating at regular intervals rather than going long stretches without food also reduces the chance of unexpected drops. Keeping a fast-acting carb source in your car, desk, gym bag, and nightstand means you’re never caught without a quick fix when you need one.