Vape liquid does contain calories, but the amount is so small that it has no meaningful impact on your daily calorie intake or body weight. The two base ingredients in e-liquid, propylene glycol and vegetable glycerin, contain roughly 4 calories per gram each. A typical vape tank holds about 2 to 5 milliliters of liquid, putting the total caloric content of a full tank somewhere around 8 to 25 calories. Even if your body absorbed every bit of it, that’s less than a single bite of an apple.
Where the Calories Come From
E-liquid is made up of just a few ingredients: propylene glycol (PG), vegetable glycerin (VG), nicotine, and flavorings. The calories come almost entirely from the two base liquids. Propylene glycol contains about 4 calories per gram, and vegetable glycerin is slightly higher at roughly 4.32 calories per gram. VG is the thicker, slightly sweet component responsible for producing visible vapor clouds, while PG is thinner and carries most of the flavor and throat hit.
The flavorings and sweeteners used in vape juice typically add zero or near-zero calories. Compounds like sucralose, aspartame, and saccharin are common in flavored e-liquids specifically because they deliver sweetness without caloric content. Nicotine itself contains no calories.
How Your Body Handles Inhaled Calories
Here’s the more important question: even though the liquid contains calories on paper, does your body actually use them as energy? The answer is complicated, but the practical result is the same: it doesn’t matter.
When you eat food, it passes through your digestive system, gets broken down into usable components, and travels to the liver before entering the wider bloodstream. Your gut is specifically designed to extract energy from what you consume. Your lungs are not. They’re built to exchange oxygen and carbon dioxide, and while they can absorb certain molecules directly into the bloodstream, they aren’t equipped to process nutrients the way your stomach and intestines are.
That said, the lungs are surprisingly efficient at absorbing small molecules. Research on pulmonary absorption shows that inhaled substances bypass the liver entirely and enter the bloodstream directly, traveling straight to the heart for distribution throughout the body. This is why inhaled medications like asthma inhalers work so quickly. So it’s theoretically possible that trace amounts of VG and PG reach your bloodstream through your lungs. But even in a best-case absorption scenario, you’re talking about a handful of calories spread across an entire day of vaping. Your body burns more energy chewing a piece of gum.
Does Vaping Affect Blood Sugar or Insulin?
If you’re asking about vape calories because you’re fasting or watching your blood sugar, the research is reassuring on this front. A study using both animal models and data from a large national health survey (NHANES) found no significant link between e-cigarette use and insulin resistance. Mice exposed to e-cigarette vapor for 12 weeks showed fasting blood glucose, insulin, and insulin resistance markers comparable to unexposed controls.
In human data, sole e-cigarette users showed no significant difference in insulin resistance or glucose tolerance compared to non-users after adjusting for factors like age, sex, physical activity, and BMI. While sole vapers had modestly higher median insulin resistance values than other groups, the differences were not statistically significant. In practical terms, vaping does not appear to trigger an insulin response or raise blood sugar in a way that would break a fast or interfere with metabolic goals.
Will Vaping Make You Gain Weight?
No. Even heavy vapers who go through several milliliters of e-liquid per day are looking at a maximum of maybe 20 to 50 calories from the liquid itself, and realistically far less than that reaches the bloodstream in usable form. To put that in perspective, you’d need to vape through hundreds of milliliters of e-liquid to match the calories in a single meal. Weight gain requires a sustained caloric surplus, and vaping simply cannot contribute enough energy to move the needle.
Nicotine itself is actually an appetite suppressant, which is one reason some people worry about weight gain when they quit vaping or smoking. The concern about vape calories tends to come from the wrong direction. The calories in the liquid are irrelevant, but the nicotine’s effect on appetite suppression can mask eating patterns that surface once you stop.