Invasive surgical procedures for gastric volume reduction or bypass have been considered the most effective approach to sustainable long-term weight reduction. However, non-invasive techniques for dynamic volume reduction from inside the stomach are lacking. The aim of this study was to propose temporary, permeable, controllable pseudobezoars for non-invasive, long-term sustainable gastric volume reduction and to test them in pilot human studies. Permeable sac-like carriers made from biocompatible and biodegradable material were filled with expandable superabsorbent fiber and polymer granules. The implements were designed to prevent the expulsion of the pseudobezoars through the pylorus for a controlled time period. The pseudobezoars were administered transorally to two human patients (2M, 78.9 kg/174 cm, girth 88.1 cm, and 89.7 kg/175, girth 95.2 cm). Body weight dynamics, girth, level of satiety, stools, bowel regularity and notable side effects were monitored in three distinct 1 month periods: baseline, therapy and washout. Sonographic verification of the presence of pseudobezoars in the stomachs of both subjects was performed at the end of the therapy month and was repeated at the end of the washout period to examine the clearance of the implements. During the therapy month, both individuals exhibited significant weight and girth reduction (p < 0.05), and substantially increased satiety levels. The patients retained their bowel regularity and did not report any notable side effects. The temporary pseudobezoars were clearly noticeable sonographically in both patients at the end of the therapy month and cleared after its discontinuation. Controllable temporary pseudobezoars were designed and tested in pilot studies.