Acesulfame Potassium
Also known as: Ace-K, Sunett
Often blended with sucralose or aspartame to mask their aftertaste. Carries its own bitter tail.
At a glance
How Acesulfame Potassium compares to table sugar on the three numbers most people actually want.
Ten-metric breakdown
See methodology →- Taste qualityWeight 20%80
- Glycemic impactWeight 18%Pending
- NaturalnessWeight 10%15
- Tooth friendlinessWeight 8%85
- Overall safetyWeight 14%Pending
- Digestive comfortWeight 8%80
- Gut microbiomeWeight 8%Pending
- AftertasteWeight 6%Pending
- SustainabilityWeight 4%Pending
- Allergen safetyWeight 4%75
Source: public.sweeteners snapshot, refreshed 2026-04-27. "Pending" cells are catalogued but not yet graded by SweetSpot research.
What it actually is
Acesulfame-K is a potassium salt of an oxathiazine. It is 200× sweeter than sucrose, calorie-free, and excreted unchanged. It is rarely used alone — its main role is masking the off-tastes of sucralose and aspartame in blends.
Recent rodent and microbiome work has flagged neurological and gut concerns, but the human data is thin and confounded. Regulatory bodies maintain its safety within ADI.
If you see two artificial sweeteners on a label and one is Ace-K, the other is doing the heavy lifting taste-wise.
- Stable in heat and across pH
- Very high ADI
- Smooths the taste of sucralose and aspartame
- Bitter / metallic aftertaste alone
- Almost always paired with another sweetener — rarely the lead
- Emerging microbiome data
Regulatory status
In practice
- Blends — rarely a standalone choice
- Microbiome concerns
Coca-Cola Zero, Pepsi Zero, many protein bars
The evidence
Selected peer-reviewed sources behind the score. Open access where possible. Read our scoring methodology for how we weight evidence tiers.
Recommended swaps
Higher-scoring alternatives that perform similarly in use.
Mogrosides from Siraitia grosvenorii. 150–250× sweeter, no glycemic effect, cleaner aftertaste than stevia.
Steviol glycosides from Stevia rebaudiana. 200–400× sweeter than sugar, zero glycemic.
A rare sugar that tastes 70% as sweet as sucrose with ~10% the calories and a negligible — sometimes mildly suppressive — insulin response.