The exponential growth of pharmaceutical consumption worldwide has generated vast quantities of expired and unused medications, posing severe threats to public health and environmental safety. Conventional disposal methods, including landfilling and incineration, often lead to soil and water contamination due to residual chemical compounds. This study investigates an unconventional yet potentially transformative approach—repurposing expired human medicines as plant growth enhancers. By drawing from sustainability principles and circular economy perspectives, this research explores how vitamins, minerals, and iron-based supplements that are expired (0–2 years beyond shelf life) can serve as alternative nutrient sources for plants. A controlled experimental design was constructed using Spinacia oleracea (spinach), Phaseolus vulgaris (bean), and Solanum lycopersicum (tomato), wherein aqueous solutions of expired multivitamins, iron, and mineral tablets were administered at varying concentrations. Within 6–8 hours of application, the treated plants displayed visible improvements in leaf turgidity, chlorophyll density, and overall freshness. Quantitative measurements taken after seven days indicated a 15–25% increase in growth indices compared to control groups. The findings suggest that many expired pharmaceutical compounds retain biochemical integrity sufficient to stimulate plant metabolism. This study not only challenges conventional perceptions of pharmaceutical waste but also proposes a low-cost, ecologically responsible solution for urban and rural horticultural practices. It advocates for further research on dosage optimization, soil interaction, and potential ecological risks to ensure safe scalability of this novel bio-recycling strategy.