After they mate, female mosquitoes need to feed on blood to provide the necessary nutrition to allow her eggs to mature. Mosquito bites are not only itchy and irritating, but mosquitoes can also potentially carry dangerous diseases such as West Nile virus. It is important to protect yourself from mosquito bites, and many tout vanilla as an effective, natural mosquito repellent.
According to the University of Wisconsin, two published studies and one informal study tested the efficacy of vanilla as a natural mosquito repellent. All found little to no repellent activity in vanillin, which is the primary component of vanilla bean extract.
The two published studies cited by the University of Wisconsin tried adding vanillin to some commercially available mosquito repellents. While ineffective as a mosquito repellent on its own, vanillin proved to be useful in increasing the efficacy of other repellents.
Much of the evidence regarding the effectiveness of vanilla as a mosquito repellent is anecdotal. Some outdoor enthusiasts maintain that vanilla is the most effective repellent they have ever used. However, most major medical studies, including a 2002 study reported in the New England Journal of Medicine, indicate that plant oil-based repellents are far less effective than those containing N,N-Diethyl-meta-toluamide, or DEET.
Because scientific studies indicate that natural remedies such as vanilla are not effective at repelling mosquitoes, the Centers for Disease Control and Prevention recommends that you use products containing DEET, Picaridin, IR3535, or oil of lemon eucalyptus for maximum mosquito bite prevention.
Manufacturers are looking for more reliable sources of flavor and fragrance ingredients. They now face price-swings and supply disruptions caused by natural disasters, poaching and other problems in the far-flung places where fragrant natural plant oils originate. Major flavor and fragrance houses thus are turning to biotechnology companies that use genetically engineered microbes to produce ingredients that mimic natural flavors and fragrances.
The microbes can produce vanillin, for instance, which is the stuff of vanilla, and picrocrocin, normally extracted from saffron, which costs about $900 a pound. Microbial production has another advantage aside from reliability, Bomgardner notes: It reduces the cost of such otherwise rare and expensive ingredients.
Besides, according to University of Wisconsin, catnip oil proves to be an effective mosquito repellent in studies. However, commercially available mosquito repellents still provide more protection.