If you’ve followed keto or low-carb diets for any length of time, you’ve probably seen allulose show up in everything from protein bars to ice cream. It has become popular because it does something many older sugar substitutes struggle with: it behaves a lot like actual sugar. Allulose can add bulk, brown during cooking, help keep baked goods moist, and improve the texture of frozen desserts while contributing far fewer calories than table sugar.
There is just one slightly confusing problem: allulose actually is a sugar.
That distinction has suddenly become much more important because companies selling foods and drinks containing allulose are being sued over claims like “zero sugar” and “sugar free.” Costco is one of the latest companies pulled into the argument over its Kirkland Signature Hydration Electrolyte Drink Mix, but lawsuits involving Chobani, David Protein, Liquid Death, Liquid I.V., WK Kellogg, KIND and other brands have raised the same basic question.
So how can allulose chemically be a sugar while a Nutrition Facts label can still show 0 grams of sugar? The answer involves the difference between chemistry, metabolism, FDA labeling policy, and what companies are allowed to claim on the front of a package.
Quick Answer: Is Allulose Sugar?
Yes. Allulose is a monosaccharide, which means it chemically qualifies as a type of sugar. However, the FDA currently allows manufacturers to exclude allulose from the Total Sugars and Added Sugars lines on Nutrition Facts labels because the body metabolizes it differently from traditional sugars. Allulose still has to be included in Total Carbohydrate.
The FDA also allows manufacturers to calculate allulose at 0.4 calories per gram instead of the standard 4 calories per gram used for conventional sugars. Where things get complicated is the separate question of whether a product containing meaningful amounts of allulose can be marketed as “sugar free” or “zero sugar.”
What Is Allulose?
Allulose, also called D-allulose or D-psicose, is a simple sugar that occurs naturally in very small amounts in foods including figs and raisins. It is often described as a rare sugar because naturally occurring quantities are tiny compared with sugars like glucose, fructose, and sucrose.
Chemically, allulose is a monosaccharide, putting it in the same broad category as glucose and fructose. Its structure is slightly different, however, and that difference changes how the human body handles it. The FDA specifically includes allulose among sugars that are metabolized differently from traditional sugars.
Allulose is only around 70% as sweet as table sugar, which means manufacturers generally need much more of it than they would need of an intense sweetener like stevia, monk fruit, or Sweelin. That sounds like a disadvantage until you are trying to make actual food.
Sugar does more than make food sweet. It provides bulk, influences moisture, contributes to browning and caramelization, and affects the freezing properties of desserts like ice cream. A few drops of stevia can sweeten coffee, but they cannot replace everything a cup of sugar was doing in brownies or caramel sauce. Allulose gets much closer, which is one reason it has become especially popular in low-carb baked goods, sauces, syrups, candy, and frozen desserts.
Is Allulose a Sugar Alcohol?
No. Allulose is not a sugar alcohol.
Erythritol, xylitol, maltitol, sorbitol and similar ingredients are sugar alcohols. Allulose is a monosaccharide that happens to be metabolized differently from more familiar sugars. The FDA treats metabolically different sugars, sugar alcohols, and high-intensity sweeteners as distinct categories.
That distinction matters because people often lump every low-carb sweetener into the same bucket even though their chemistry, digestive effects, sweetness, and usefulness in cooking can be very different.
Why Does Allulose Show 0 Grams of Sugar on Nutrition Labels?
This is the part that makes the current lawsuits sound completely ridiculous until you understand the labeling rules.
In 2020, the FDA issued final guidance explaining that it intended to exercise enforcement discretion so manufacturers could exclude allulose from both Total Sugars and Added Sugars on Nutrition Facts labels. The FDA reached that position after reviewing evidence involving allulose’s metabolism, caloric value, glycemic response, and effects on dental health.
Allulose still has to be included in Total Carbohydrate. The FDA also allows companies to calculate its caloric contribution using 0.4 calories per gram rather than the standard 4 calories per gram normally assigned to carbohydrates. You can read the FDA’s full allulose labeling guidance here.
That means a simplified Nutrition Facts panel could theoretically look something like this:
- Total Carbohydrate: 8g
- Total Sugars: 0g
- Added Sugars: 0g
- Allulose: 8g
The allulose has not somehow vanished from the food. FDA policy simply allows it to be treated differently on the specific sugar lines because it behaves differently in the body.
If you are now wondering whether allulose is technically sugar or technically not sugar, congratulations: you have arrived at the exact disagreement currently keeping several attorneys employed.
Why Are “Zero Sugar” and “Sugar-Free” Allulose Products Being Sued?
The legal mess comes from the difference between how allulose can be displayed inside the Nutrition Facts panel and what companies are allowed to say about the entire product on the front of the package. Those sound like the same question, but under federal food-labeling rules they are not necessarily identical.
The case that pushed the issue into much greater prominence involved Chobani Zero Sugar yogurt. Consumers Jason and Abigail Franco sued Chobani after buying yogurt marketed as “sugar free” even though each serving contained four grams of allulose. A lower federal court dismissed the case, but the Seventh Circuit Court of Appeals reversed that dismissal in July 2026.
The appeals court concluded that the relevant federal regulation defines sugars broadly enough to include allulose because allulose is a monosaccharide. The court therefore allowed the consumers’ deception claims to proceed.
That does not mean the court issued a final ruling that Chobani deceived consumers or owes anyone damages. It means the lawsuit survived dismissal and can continue, which is an important distinction given how quickly “someone filed a lawsuit” tends to mutate into “court proves product is dangerous” once it reaches social media.
The ruling nevertheless created a real issue for companies using allulose. FDA guidance currently allows manufacturers to exclude it from Total Sugars and Added Sugars on the Nutrition Facts panel, while the regulation governing a “sugar free” claim treats all monosaccharides as sugars. FDA enforcement discretion over the Nutrition Facts panel does not necessarily provide immunity from private lawsuits challenging marketing claims elsewhere on the package.
Which Companies Have Been Sued Over Allulose?
Chobani was not the end of it. In September 2026, FoodNavigator reported a wave of proposed class-action lawsuits involving allulose-containing products marketed as having zero or no sugar.
| Company or brand | Issue raised in litigation | Status |
|---|---|---|
| Chobani | “Zero Sugar” yogurt containing allulose | Federal appeals court allowed the lawsuit to proceed |
| David Protein | Zero-sugar claims on products containing allulose | Proposed class action |
| Liquid Death | Zero-sugar claims on products containing allulose | Proposed class action |
| Liquid I.V. | Sugar-related marketing of allulose-containing products | Proposed class action |
| WK Kellogg | Zero-sugar claims involving allulose | Proposed class action |
| KIND | Sugar-related marketing involving allulose | Proposed class action |
| Costco | “Sugar-free” Kirkland Signature Hydration mix containing allulose | Proposed class action |
Costco became one of the latest companies pulled into the issue after a proposed class action challenged the labeling of its Kirkland Signature Hydration Electrolyte Drink Mix. According to reporting on the Costco lawsuit, the plaintiff argues that calling the mix sugar-free is misleading because allulose is its primary ingredient.
These cases are allegations, not findings that the companies violated the law. The broader significance is that allulose labeling has moved beyond an obscure regulatory question and into a much larger argument about what consumers reasonably think “zero sugar” means.
Is Allulose Keto-Friendly?
Allulose is generally considered compatible with a ketogenic diet because it contributes very little usable energy and has a much smaller effect on blood glucose and insulin than conventional sugar. That does not mean allulose stops being chemically classified as a sugar. Both things can be true at once.
This is why I would not use the question “Is it technically a sugar?” as the deciding factor when evaluating whether a sweetener works for keto. The more practical questions are how much usable carbohydrate it contributes, how strongly it affects glucose and insulin, how much you are eating, and what else is in the finished food.
The FDA still requires allulose to be included in Total Carbohydrate, which can make labels confusing for people calculating net carbs. Many low-carb products subtract allulose when reporting net carbs because relatively little of it is metabolized for energy, but “net carbs” itself is not a nutrient category defined by the FDA.
A food also does not automatically become keto-friendly just because allulose replaced the sugar. A cookie can be sweetened entirely with allulose and still contain enough flour or starch to blow through someone’s daily carb target.
If you are new to the diet itself, my Pescatarian Keto Diet guide goes into how carb restriction and ketosis actually work. You can also read my guide to telling when you are in ketosis if you are trying to understand how people monitor their individual response.
Does Allulose Raise Blood Sugar or Insulin?
Current human research suggests that allulose produces a very different glucose and insulin response from conventional sugar.
A 2026 systematic review and meta-analysis identified 20 controlled human trials involving rare sugars, including 12 trials studying allulose. Across the allulose studies, researchers found significant reductions in post-meal glucose and insulin responses.
The same analysis did not find significant improvements in HbA1c, fasting glucose, fasting insulin, blood lipids, uric acid, or body composition. In other words, the evidence is encouraging if your main reason for using allulose is replacing conventional sugar without producing the same immediate glucose response. It is not evidence that putting allulose into everything you eat will somehow fix your overall metabolic health.
That is less exciting than discovering the correct sweetener makes you immortal, but nutrition research continues to refuse to cooperate with marketing departments.
Does Allulose Have Side Effects?
The most common practical issue with allulose is gastrointestinal tolerance. Like several other alternative sweeteners, larger amounts can cause symptoms such as bloating, abdominal discomfort, or diarrhea in some people.
A 2026 randomized 30-day study followed 50 healthy adults consuming either 24 or 36 grams of allulose per day. About 48% reported gastrointestinal symptoms, although researchers described those symptoms as mild and temporary and found that they occurred most frequently during the first few days.
That does not mean half of everyone who eats a product containing allulose will feel sick. The study involved fairly substantial daily doses, and people vary considerably in how well they tolerate alternative sweeteners. It does mean that “low calorie” and “low sugar” should not be interpreted as permission to treat an entire bag of candy as a serving.
Your digestive system may provide a considerably faster product review than anything Amazon has to offer.
Allulose vs. Erythritol, Stevia, Monk Fruit, and Sweelin
All of these sweeteners can help reduce conventional sugar, but they solve very different formulation problems. That is why I do not think there is one objectively perfect keto sweetener.
| Sweetener | What it is | Relative sweetness | Provides bulk? | Common keto uses |
|---|---|---|---|---|
| Allulose | Rare sugar | About 70% as sweet as sugar | Yes | Baking, sauces, syrups, caramel, frozen desserts |
| Erythritol | Sugar alcohol | About 60-80% as sweet as sugar | Yes | Baking, chocolate, granulated sweetener blends |
| Stevia | Plant-derived steviol glycosides | About 200-300× sugar | No | Drinks, drops, packaged foods, baking blends |
| Monk fruit | Fruit-derived mogrosides | About 100-250× sugar | No | Drinks, packaged foods, granulated blends |
| Sweelin | Sweet protein | About 3,000-3,500× sugar | No | Emerging packaged-food applications |
Exact sweetness varies by concentration and formulation, but the more important difference is what happens when you actually try to make food with these ingredients.
Allulose vs. Erythritol
Erythritol is a sugar alcohol, while allulose is a rare sugar. Both became popular in low-carb foods because they can replace some of sugar’s bulk without producing the same glucose response as sucrose.
Erythritol has a noticeable cooling sensation that some people dislike, and it can recrystallize in certain recipes. Allulose tends to behave more like conventional sugar when browning, caramelization, or keeping frozen desserts softer matters.
If you specifically want erythritol, you can find erythritol sweetener on Amazon. I’ve also used and recommended NOW Foods Erythritol as a straightforward granulated option.
Allulose vs. Stevia
Stevia is dramatically sweeter than allulose, which makes it useful when sweetness is basically the only job you need the ingredient to perform. A few drops can sweeten coffee or tea without contributing meaningful bulk.
The problem appears when you try to replace sugar in a food where sugar was doing more than tasting sweet. Removing a cup of sugar from brownies and replacing it with several drops of stevia leaves you with a rather obvious physics problem.
For coffee, tea, and similar uses, SweetLeaf stevia remains one of the easiest low-carb options to keep around.
Allulose vs. Monk Fruit
Monk fruit is another high-intensity sweetener, so it is frequently blended with a bulk sweetener to make it easier to measure and use. You can buy monk fruit sweetener on Amazon, but it is worth checking the ingredient list because many granulated monk fruit products contain another sweetener as their primary ingredient.
I’ve included Lakanto Monkfruit Sweetener on my pescatarian keto food shopping list because granulated blends are much easier to use when you want something closer to conventional sugar.
Allulose-and-monk-fruit blends are also becoming more common. The combination makes sense because monk fruit can add more sweetness while allulose contributes some of the bulk and physical behavior missing from a high-intensity sweetener on its own.
Allulose vs. Sweelin
Sweelin is almost the opposite of allulose from a formulation perspective. It is a precision-fermented sweet protein that is thousands of times sweeter than sugar, so manufacturers need an extremely small amount of it. Allulose is less sweet than sugar and is used in much larger quantities, but those larger quantities are useful when you need volume, moisture, browning, or freezing behavior.
I recently wrote a full guide explaining what Sweelin is and whether the new sweet protein appears keto-friendly. The two ingredients could eventually complement each other rather than compete directly.
A future low-sugar frozen dessert, for example, could theoretically use a high-intensity sweetener to provide sweetness while using allulose for some of the physical properties that conventional sugar normally contributes. Food formulation is unfortunately more complicated than finding the objectively Best Sweet Molecule and declaring the game over.
Can You Buy Allulose for Keto Baking?
Yes. Unlike Sweelin, allulose is already easy to buy as a consumer sweetener, and it is particularly useful if you make low-carb desserts where sugar’s physical properties matter.
You can buy allulose sweetener on Amazon if you want to experiment with it directly. It can work particularly well in applications such as baked goods, sauces, syrups, caramel, and homemade low-carb ice cream.
A plain allulose product lets you see how the ingredient itself behaves, while blends can make the sweetness level closer to conventional sugar. Because allulose is less sweet than sucrose, products that combine it with monk fruit or another intense sweetener can provide more familiar sweetness without requiring even more allulose.
For other options, these are the low-carb sweeteners mentioned throughout this guide:
- Allulose: Useful when you want something that behaves more like real sugar. Shop allulose on Amazon.
- Stevia: Best when you mainly need sweetness rather than bulk. Shop SweetLeaf stevia on Amazon.
- Monk fruit: A high-intensity sweetener commonly sold in blends. Shop monk fruit sweetener on Amazon.
- Lakanto Monkfruit Sweetener: A granulated option that is easy to measure in recipes. Shop Lakanto Monkfruit Sweetener on Amazon.
- Erythritol: A sugar alcohol that provides bulk but behaves differently from allulose in cooking. Shop erythritol on Amazon.
- NOW Foods Erythritol: A straightforward granulated erythritol option. Shop NOW Foods Erythritol on Amazon.
You can also find sweeteners and other low-carb pantry staples in my Pescatarian Keto Food Shopping List. If you are mostly interested in packaged foods rather than baking ingredients, my guide to the best keto snacks to buy includes several products where checking the specific sweetener and full ingredient list is useful.
I would choose among these based on what you are actually making rather than trying to identify one universally superior option. Sweetening coffee is a different problem from replacing sugar in cookies, and replacing sugar in cookies is a different problem from trying to make low-carb ice cream scoopable instead of turning it into a brick capable of damaging structural concrete.
Should You Avoid Allulose Because It Is Technically Sugar?
I would not decide whether to use allulose entirely based on whether chemistry or federal regulations call it a sugar. That question matters a great deal if you are a food company printing SUGAR FREE across the front of a package and your legal department suddenly wishes you had chosen a different font, but it does not tell you everything you need to know about how the ingredient behaves in your body.
Allulose is chemically a sugar. It also contributes far fewer calories than sucrose, produces a very different glucose and insulin response, and is commonly used in low-carb foods for exactly those reasons. Those facts do not contradict each other.
The current lawsuits are primarily forcing companies, regulators, and courts to sort out what phrases like “zero sugar” and “sugar free” are allowed to mean when allulose is present. They have not suddenly uncovered evidence that allulose secretly behaves exactly like table sugar once nobody is looking.
If you follow keto, I would still treat the entire nutrition label and ingredient list as more useful than whatever marketing phrase is printed largest on the front. That advice has aged remarkably well.
More Pescatarian Keto Resources
- What Is Sweelin? Is the Sweet Protein Keto-Friendly?
- Pescatarian Keto Food Shopping List
- Best Keto Snacks to Buy
- Pescatarian Keto Diet: Benefits, Food List & How to Start
- How to Tell When You Are in Ketosis
Frequently Asked Questions About Allulose
Is allulose actually sugar?
Yes. Allulose is a monosaccharide, which means it is chemically a simple sugar. The FDA nevertheless permits manufacturers to exclude it from Total Sugars and Added Sugars on Nutrition Facts labels because it is metabolized differently from conventional sugars. It still has to be included in Total Carbohydrate.
Why does allulose say 0 grams of sugar?
FDA guidance allows manufacturers to exclude allulose from Total Sugars and Added Sugars even though allulose itself is chemically a sugar. The policy reflects differences in allulose’s metabolism, caloric value, and glycemic response. Allulose must still be included in Total Carbohydrate.
Is allulose keto-friendly?
Allulose is generally considered keto-friendly because relatively little of it is metabolized for energy and human research shows a much smaller glucose and insulin response than conventional sugar. A product containing allulose is not automatically keto-friendly, however, because other ingredients may still contribute substantial carbohydrates.
Does allulose count as carbs?
Yes. FDA guidance requires allulose to be included in Total Carbohydrate on Nutrition Facts labels, although manufacturers may exclude it from Total Sugars and Added Sugars.
Is allulose a sugar alcohol?
No. Allulose is a monosaccharide, or simple sugar. Erythritol, xylitol, maltitol, sorbitol and similar ingredients are sugar alcohols.
Does allulose raise blood sugar?
Human studies suggest that allulose produces a much smaller post-meal glucose response than conventional sugar. A 2026 systematic review and meta-analysis found significant reductions in post-meal glucose and insulin responses across controlled allulose trials, although it did not find significant improvements in longer-term measures such as HbA1c or fasting glucose.
Why are companies being sued over allulose?
Several proposed class-action lawsuits allege that products containing allulose are misleadingly marketed as “zero sugar” or “sugar free” because allulose falls within the federal regulatory definition of sugar. A July 2026 federal appeals court decision allowed a lawsuit involving Chobani Zero Sugar yogurt to proceed, which helped trigger additional cases involving other brands.
Is allulose better than erythritol?
Neither sweetener is objectively better for every use. Allulose behaves more like conventional sugar in baking, browning, caramelization, and frozen desserts, while erythritol is inexpensive and works well in many granulated sweetener blends. They also have different chemistry and can produce different digestive effects.