Sweeteners
Mannitol
Definition
What it is
Sugar alcohol: commonly found in 'sugar-free' products; can cause gas, bloating, and diarrhea at moderate doses; maltitol and sorbitol still raise blood glucose. Most sugar alcohols are high-FODMAP polyols (the 'P' in FODMAP); sorbitol and mannitol are the primary triggers, while xylitol, maltitol, isomalt, and lactitol all carry similar GI risk in sensitive individuals.
On the label
How it appears on labels
- mannitol
Regulation
Regulatory status
No bans or restrictions are recorded for this ingredient in the jurisdictions clearlabel tracks (US, EU, UK, Canada, Japan, Australia/NZ, Brazil).
Explainer
In plain language
Mannitol is a sugar alcohol, a type of sweetener that occurs naturally in some fruits and vegetables and is also made commercially. It tastes sweet but delivers fewer calories than sugar and is often used in sugar-free products and as an anti-caking or bulking agent. Because the body absorbs it slowly and incompletely, much of it passes into the lower gut.
Assessment
Why it is flagged
Mannitol is a polyol, the 'P' in the FODMAP framework, and along with sorbitol it is one of the sugar alcohols most associated with gas, bloating, and diarrhea when eaten in moderate amounts. The effect is dose-dependent and varies a lot from person to person, which is why US products with significant amounts carry a laxative-effect notice. Unlike some sugar alcohols such as maltitol and sorbitol, mannitol has a smaller effect on blood glucose, though this varies. The digestive effects are well documented rather than disputed, but individual tolerance differs widely. Clear Label flags mannitol at low severity so people who track bloating or loose stools can see whether it lines up with their own logs.
In the aisle
Where it commonly shows up
- Sugar-free candy and mints
- Sugar-free gum
- Sugar-free chewable tablets and supplements
- Some diet and reduced-sugar baked goods
- Dusting on some dried fruits and confections
Practical
Reading the label
Mannitol is listed by name and may also appear as E421 in the EU. A general 'may have a laxative effect' or 'excess consumption may cause a laxative effect' note near the ingredient list is a common signal that a sugar alcohol like mannitol is present in a meaningful amount.
Alternatives
If you want to avoid it
Some people who react to polyols choose products sweetened with non-polyol options like stevia or monk fruit, or plain unsweetened versions. Since tolerance is individual, comparing how you feel after different sweeteners is the practical test.
FAQ
Common questions
Why does mannitol cause bloating or diarrhea?
The body absorbs mannitol slowly and incompletely, so much of it reaches the large intestine where it draws in water and is fermented by gut bacteria. This is a known dose-dependent effect, though the threshold that bothers someone varies widely.
Does mannitol raise blood sugar?
Mannitol has a smaller effect on blood glucose than sugar, which is part of why it appears in sugar-free products. Some other sugar alcohols, like maltitol and sorbitol, raise blood glucose more, so they are not interchangeable.
Is mannitol a FODMAP?
Yes. Mannitol is a polyol, the 'P' in FODMAP, and it is one of the polyols most likely to trigger symptoms in people who are sensitive. Many people following a low-FODMAP approach watch for it and for sorbitol in particular.
Citations
Sources
Citation
Primary reference
About this page: the definition, label names, severity, and regulatory chips come from the clearlabel ingredient taxonomy, the same data the scanner uses to score products. Research summaries describe associations reported in published studies, not diagnoses; individual responses vary. Scan any product with clearlabel to see which of its ingredients carry flags.