Patchouli oil cream blocks Aedes aegypti bites for three hours

Scientists formulated a topical cream using patchouli (Pogostemon cablin) essential oil and tested it against the mosquito Aedes aegypti, a major vector of dengue, Zika, chikungunya and yellow fever. In a controlled laboratory trial, a concentration of 200 ppm of the patchouli‑alcohol‑rich extract provided 100 % protection for the full 180‑minute observation period, preventing mosquito landing and biting.

The study compared the patchouli cream with a commercial DEET‑based repellent and a neutral solvent. Fifty adult female mosquitoes were placed in cages, and healthy volunteers applied the cream to their forearms; observations were recorded every 30 minutes for three hours. Chemical analysis identified 16 constituents, with patchouli alcohol accounting for about 40 % of the oil. The formulation remained stable in colour, odour and pH after 90 days of storage under varied temperature and light conditions, indicating suitability for practical use. Researchers note that the results are preliminary and derived from laboratory conditions, and field efficacy may differ due to factors such as sweat, humidity and skin friction.