Creating impact in labs oriented at sustainability transformations is challenging. Combining the experiences of ten projects and sharing the insights in “Labbing”, gained through engaging in various activities within transformation-oriented Labs from the fields of agriculture, food, and healthcare, the author team established a Community of Practice at the Vrije Universiteit Amsterdam, to identify impact challenges inductively and recommend practical strategies for addressing these.While the issue of creating impact in real-world labs for experimenting with sustainability transformation has been studied, little is known about how to assess and understand impact in practice. Deciding on “what counts as impact” is challenging as problem definitions and solutions are political and contested. In our research projects for sustainability transformations in fields such as agriculture, food, and healthcare, we encountered typical questions of creating impact in real-world labs. We established a Community of Practice to explore the different challenges pertaining to these impact questions. We identified four overarching challenges related to impact: 1. measuring the impact of Labs, 2. dealing with positionality and power dynamics, 3. fostering impact within and beyond projects, and 4. ensuring impact across different contexts. This paper offers practical strategies for responding to these challenges: 1. tailor-made training for Labbing, 2. reflexively engaging with power dynamics, 3. forging rich, translocal learning and impact. Sharing learnings from our experience with Labbing may broaden the repertoire of fellow Lab practitioners in enhancing and strengthening their impact.