Abstract
SAS(®) is commonly used for bioequivalence (BE) data analysis. R is a free and open software for general purpose data analysis, and is less frequently used than SAS(®) for BE data analysis. This tutorial explains how R can be used for BE data analysis to generate comparable results with SAS(®). The main SAS(®) procedures for BE data analysis are PROC GLM and PROC MIXED, and the corresponding R main packages are "sasLM" and "nlme" respectively. For fixed effects only or balanced data, the SAS(®) PROC GLM and R "sasLM" provide good estimates; however, for a mixed-effects model with unbalanced data, the SAS(®) PROC MIXED and R "nlme" are better for providing estimates without bias. The SAS(®) and R scripts are provided for convenience.