The evidence simply is not there for the effectiveness of botanical products and skin creams containing repellent.
For example:
1. The Apr '03 issue of "Consumer Reports" found that the DEET repellents 3M Ultrathon, Off! Deep Woods for Sportsmen & Muskol Ultra 6 Hours finished on top, followed by BugOut, Sawyer Controlled Release, Cutter Unscented, Off! Skintastic with Sunscreen SPF 30, Cutter Skinsations & Avon Skin So-Soft Bug Guard/ Sunblock, in that order. Those relying on plant oils such as citronella, soybean, coconut, and geranium "provided little if any protection."
2. Published research support that DEET is more effective than Avon's Skin So Soft & plant oils ---->
http://www.lcmcd.org/relellents.pdf
3. "From 07/02 "New England Journal of Medicine:"
"Comparative Efficacy of Insect Repellents against Mosquito Bites
Mark S. Fradin, M.D., and John F. Day, Ph.D.
ABSTRACT
Background: The worldwide threat of arthropod-transmitted diseases, with their associated morbidity and mortality, underscores the need for effective insect repellents. Multiple chemical, botanical, and "alternative" repellent products are marketed to consumers. We sought to determine which products available in the United States provide reliable and prolonged complete protection from mosquito bites.
Methods: We conducted studies involving 15 volunteers to test the relative efficacy of seven botanical insect repellents; four products containing N,N-diethyl-m-toluamide, now called N,N-diethyl-3-methylbenzamide (DEET); a repellent containing IR3535 (ethyl butylacetylaminopropionate); three repellent-impregnated wristbands; and a moisturizer that is commonly claimed to have repellent effects. These products were tested in a controlled laboratory environment in which the species of the mosquitoes, their age, their degree of hunger, the humidity, the temperature, and the lightdark cycle were all kept constant.
Results: DEET-based products provided complete protection for the longest duration. Higher concentrations of DEET provided longer-lasting protection. A formulation containing 23.8 percent DEET had a mean complete-protection time of 301.5 minutes. A soybean-oilbased repellent protected against mosquito bites for an average of 94.6 minutes. The IR3535-based repellent protected for an average of 22.9 minutes. All other botanical repellents we tested provided protection for a mean duration of less than 20 minutes. Repellent-impregnated wristbands offered no protection.
Conclusions: Currently available non-DEET repellents do not provide protection for durations similar to those of DEET-based repellents and cannot be relied on to provide prolonged protection in environments where mosquito-borne diseases are a substantial threat."
In short, products containing DEET were clearly the most effective, while formulated from plant oils dont last as long and might require several applications.
SC Johnsons OFF! Deep Woods, which contains 23.8 percent DEET, kept the bugs at bay for about five hours. A milder formula, Sawyer Controlled Release, with 20 percent DEET, worked for nearly four hours. Skintastic, where the DEET concentration is 6.65 percent, provided protection for almost two hours. Other products that use citronella, an oil made from dried cultivated grasses, and IR3535, a pesticide used in Europe for more than 20 years, were shown to be far less effective."
Best regards.
DocVikingo