This study contributes to the literature on the role of communities of learners in the professional development of physics teachers. It offers insights from the "Collabora--A Community of Learners on Laboratory Work" program, designed to enhance the use of laboratories in secondary school physics teaching. The program's foundation rested upon two pillars: a learning community approach and action research, grounded in the findings of physics education research. Furthermore, the program was structured to encompass the core features of effective professional development as outlined in the literature (content focus, active learning opportunities, coherence with teachers' needs, and sufficient duration). The program spanned 2 years. During the first year, teachers engaged with and discussed different types of experiments, reflected on the assessment of scientific practices, and participated in action research aimed at improving laboratory activities in their classrooms. In the second year, they focused on integrating laboratory work within teaching-learning sequences developed through a backward design process. The research questions of this study were centered on examining the role and relevance of program features, with particular emphasis on the learning community and action research components, and on investigating the changes reported by teachers as a result of participating in the program. The findings emphasize the pivotal role of the teacher community, with reciprocal training identified as the "truly developmental" element. Moreover, they corroborate the relevance of action research in fostering a sense of ownership of research-based innovations. Over the course of the program, teachers reported changes in the personal domain, in the domain of practice, and, particularly in the second year, also in the domain of student outcomes. These changes included the use of different types of experiments, a greater sense of self-efficacy in the laboratory, and an increased focus on the design and assessment of laboratory work. We studied changes through a "growth" lens, both at the group level and within a subset of individual case studies. The latter analysis highlights different possible productive pathways to teachers' growth, supporting a view of teacher professional development as complex and multifaceted. The program structure facilitated the processes of" enactment" and "reflection" that mediated the various changes.