•Proteins produced by ectopic circRNA expression are prone to artefacts by exon concatemerization.•circRNA-specific RiboSeq reads are likely noise and not signal.•circRNA-derived peptides identified by mass-spec are typically false discoveries. Within recent years, circular RNAs (circRNAs) have been an attractive new field of research in RNA biology and disease. Consequently, numerous studies have been published towards the disclosure of circRNA biogenesis and function. Initially, circRNAs were described as a subclass of cytoplasmic non-coding RNA, however, a few recent observations have proposed that circRNAs may instead be templates for protein production. The extent to which this is the case is currently debated, and therefore using rigorous data analysis and proper experimental setups is instrumental to settle the current controversies. Here, the conventional experiments used for detecting circRNA translation are outlined, and guidelines to distinguish signal from the inherent noise are discussed. While these guidelines are specific for circRNA translation, most also apply to other aspects of non-canonical translation.