Early mammalian embryogenesis represents a central question in life sciences, yet its molecular regulation has long been inferred primarily from transcriptomic and translatomic analyses. Recently, a study by Zhu et al. (2025) based on low-input proteomic approaches systematically charted protein dynamics from oocytes to blastocysts in both mice and humans, further interrogating molecular signatures of developmentally compromised human embryos at the single-embryo level. This work not only substantially expands proteome coverage during early development, but also reveals a pervasive uncoupling between transcriptional activation, translational initiation, and protein accumulation. These findings provide new perspectives on the relationship between zygotic genome activation (ZGA) and lineage specification. This paper discussed the central role of low-input proteomics in this study, highlighted its implications for reshaping current paradigms of early embryonic development, and considered its potential applications across broader areas of biomedical research.