This review examined natural compounds that could potentially be developed into new drugs to treat parasitic worm infections in humans and animals. The researchers found relatively few promising new compounds, with most studies focusing on plant sources despite bacteria historically providing better drug candidates. The findings have important implications for addressing growing drug resistance in parasitic worm treatments. Key impacts on everyday life: • Growing resistance to existing dewormers threatens both human health and livestock production • New drug development is crucial to maintain effective treatment options for parasitic infections • Natural compounds remain an important source of potential new medicines • Better research infrastructure could accelerate discovery of new treatments • Sustainable sourcing of natural compounds affects medicine availability and cost