Lee, M.; Fraefel, C.; Eichwald, C.; Aguilar, C.

Background Oral gavage is the standard method for delivering drugs and other substances orally in rodent studies, but it can cause significant stress and risk injury. To improve animal welfare and reduce confounding stress effects, this study aimed to replace oral gavage by developing and testing a new voluntary ingestion method that is easy to adopt, minimizes stress in mice, and is suitable for a wide range of compounds. Results We developed a soft agar formulation with an appealing scent and taste that mice readily consumed without fasting or restraint. We called this method unconstrained dosing agar (UDA). Analysis of fecal corticosterone levels demonstrated that the method is associated with low stress in the animals. After training, mice quickly consumed the agar units. Body weight gain was unaffected by the treatment. Conclusions This study introduces a simple, low-stress method for administering substances orally in mice. By encouraging voluntary consumption and removing the need for fasting or restraint, this method provides a practical alternative to oral gavage and could improve animal welfare and experimental consistency.