Citronella oil is one of the most common “natural mosquito repellent” ingredients on the market and has long been used in Asian traditions for insect repellency, incense, and folk remedies. After the 20th century, with the widespread adoption of the chemical mosquito repellent DEET, citronella oil was temporarily sidelined; however, in recent years, as demand for “plant-based” and “natural mosquito repellents” has risen, it has once again become a popular ingredient in the public eye. But can it truly replace chemical mosquito repellents?