Ivermectin is an attractive cancer drug candidate as it’s inexpensive and already clinically approved, albeit for parasitic infections. Some preclinical studies have indeed found promising results using ivermectin, but these studies were done in cell cultures and animals, not in humans. As such, they cannot provide sufficient evidence that ivermectin helps treat cancer in people. Further studies are needed to reliably determine ivermectin’s effectiveness and safety when used to treat cancer in humans.