Described is a unit for releasing product for extraction or infusion beverages in containers (2) forming single-use capsules (3) comprising: at least one seat (S1) for containing a predetermined dose (33) of product having side walls; a device (6) for feeding the product in the containing seat (S1) to define the dose (33); a device (70) for compressing the product in the containing seat (S1); a device (10) for moving the seat (S1) along a closed path (PS); a device (71) for ejecting the dose from the containing seat (S1); a unit (15) for controlling and operating the compacting device (70) and the ejection device (71); the control and operating unit (15) being configured for controlling the compacting device (70) with a force such as to produce a compression which causes a coupling of the dose (33) with the side walls of the containing seat (S1) which prevents, in the operating condition of the unit, the escape of the dose from the containing seat (S1) in the absence of actions mechanical for pushing on the dose.