Background: We draw on both interdisciplinary enhancement substance use research and critical drug studies scholarship to reconceptualise enhancement substance use. Our critical discourse approach illuminates how a variety of substances are positioned as tools for self-improvement. In reconceptualising enhancement substance use, we ask what different substances can be positioned as providing enhancement? How are they positioned as tools for achieving enhancement or self-improvement goals? What discursive repertoires are employed to achieve these aims? Methods: Forty interviews were conducted with people who use substances, such as ayahuasca, psilocybin, cocaine, alcohol, nootropics and non-prescription pharmaceuticals, including Adderall and modafinil. To explore the meanings of and motivations for substance consumption, we apply the sociocognitive approach (SCA) pioneered by Teun van Dijk (2014; 2015) and examine language through the triangulation of cognition, discourse and society. We analyse how different substances are positioned as tools for achieving enhancement or self-improvement goals. Results: We identify three distinct discursive repertoires that frame substance use as enhancement: the discourse of transformation, the discourse of healing and the discourse of productivity. When accounting for enhancement substance use, our participants employ a number of discursive strategies, including ideological polarisation or ‘othering’, analogies, examples, maxims, metaphors and figurative speech. We also find evidence of interdiscursivity with most participants drawing on more than one discourse when speaking about how substances are positioned as providing enhancement. Conclusion: We conclude that the concept of enhancement has wider applicability than current understandings allow. We argue that if we reframe all substance use as providing enhancement or achieving a self-improvement goal, we have the potential to destigmatise substance use and eliminate the over-simplistic binaries that surround it.