Psicose

D-Psicose (C₆H₁₂O₆), also known as D-allulose or simply allulose, is an epimer of fructose that is used by some commercial food and beverage manufacturers as a low-calorie sweetener. Allulose occurs naturally in small quantities in a variety of foods. It was first identified in the 1940s, although the enzymes needed to produce it on an industrial scale were not discovered until the 1990s.

The U.S. Food and Drug Administration (FDA) has accepted a petition for generally recognized as safe (GRAS) for allulose as a sugar substitute in various specified food categories. Because it is absorbed and metabolized differently from other sugars, the FDA has exempted allulose from the listing of total and added sugars on the Nutrition and Supplement Facts labels, but requires its weight listing as a carbohydrate, with 0.4 kcal/g (about 1/10 the calories of ordinary carbohydrates).

Studies have shown the commercial product is not absorbed in the human body the way common sugars are and does not raise insulin levels, but more testing may be needed to evaluate any other potential side effects. In 2020, the U.S. FDA accepted the conclusion by Samyang that the maximum tolerable consumption for a 60 kg adult was 33 to 36 grams per day.