This study examined how science teachers' knowledge of research methods, neuroscience and drug addiction changed through their participation in a 5-day summer science institute. The data for this study evolved from a four-year NIH funded science education project called Addiction Research and Investigation for Science Educators (ARISE). Findings were based on pre- and post-test evaluation data from three annual cohorts in June 2010, 2011 and 2012. Researchers found significant improvement in teacher knowledge overall and on all subscales. Teachers with lower pre-test scores showed the greatest gain in post-test scores. What made this in-service unique was that the 5E pedagogical model was used to teach the teachers and demonstrate 5E instruction in the science classroom. Through the use of the 5E teaching method, we found that teachers in our cohorts with the least skill had higher rates of gain. A strategy that has been used extensively to teach science to children, this model moves away from didactic methods of in-service pedagogy. These findings suggest that the 5E model could be an effective way to teach teachers as well as students, particularly new and/or less skilled teachers, who often tend to have high numbers of English Learner (EL) students in their classes.