Although we prescribe the same medication for patients with similar diagnoses and disease patterns at the molecular level, drug responses may often show significant variation in efficacy, effectiveness, and predictability of outcomes. On various theoretical as well as clinical backgrounds, while the genetic and environmental factors confirm this theory to some extent, recent advances in systems biology and enhanced conceptualization in cell signalling technologies have highlighted the role of stochastic processes, especially the molecular noise, as a critical determinant.

This review article briefs the nature, origin, and implications of the role of molecular noise in drug response. This further explains the integrated findings from single-cell analyses, theoretical modelling, and confirmed clinical scenarios across various therapeutic sections. Based on the available data, the Intrinsic and extrinsic noise contribute to heterogeneity in signal transduction, gene expression, and the behaviour of the receptor, which ultimately affects the therapeutic outcomes. Also, understanding the possibility of artificial intelligence and advanced technologies for analyzing the molecular anchoring of the cell, its protein layer, and the organelle, the concept of stochastic variability will be incorporated into everyday clinical practice sooner, with better outcomes.