Gelesis is a biotechnology company located in Boston, Massachusetts that developed the weight loss device Gelesis100 (Plenity) for use in overweight and obesity.

The company produces Gelesis100, which is a superabsorbent hydrogel capsule that expands in the stomach, creating a feeling of fullness, helping people reduce the amount of food they eat.

[3] Gelesis Holdings, Inc. together with its two affiliates, filed for voluntary Chapter 7 liquidation in the United States Bankruptcy Court for the District of Delaware on October 30, 2023.

[4] The company's technology was co-invented by Alessandro Sannino, a professor of engineering at the University of Salento, who had been researching the idea prior to the launch of Gelesis.

[16][17] In January 2022, the company completed a business combination with Capstar Special Purpose Acquisition Corp. and commenced trading on the New York Stock Exchange under the ticker symbol “GLS.