A study done on the effectiveness of the topical application of mosquito repellents made of lemongrass oil, both cream and ointment forms, by the Department of Pharmaceutics, Obafemi Awolowo University, Ile-Ife, Nigeria, found that the formulations were 50 percent effective and lasted for two to three hours.

On the Other: Soap is not an ideal method of application

The same study on lemongrass as a mosquito repellent noted that it was more effective when used with a hydrophilic (water loving) base, making a wet wipe infused with the repellent an ideal choice. Additionally, lemongrass as a mosquito repellent in soap may prove ineffective because you are immediately rinsing the formula away from the skin and the University of Florida, IFAS Extension, tells us that activities involving water such as perspiration and rainfall have the ability to decrease the repellent's effectiveness.

Bottom Line

Lemongrass soap may provide you with limited relief from mosquitoes depending on the area in which you live and the species of mosquitoes. Using other formulations of lemongrass repellents such as creams, ointments and wipes will provide protection comparable to that of commercial repellents containing DEET.

Source:

National Institutes of Health: Formulation of an Effective Mosquito-Repellent Topical Product from Lemongrass Oil

Florida Cooperative Extension Service: Mosquito Repellents

Word Contructions: Hydrophilic Substances