Many travelers, especially those with chemical sensitivities, are reluctant to apply Deet, a potent and somewhat toxic chemical, to bare skin. Some turn to natural alternatives. But are any of these natural substances anywhere near as effective as Deet at preventing mosquito bites? When I asked an Australian doctor in
The chemical industry, much like the drug industry, has little incentive to popularize non-chemical-based preventive measures. In other words, supposing there were a natural alternative to Deet that had been scientifically proven just as effective, it probably would not be very well publicized. The fact is that the chemical-pharmaceutical complex dominates the media-marketing-information channels in our society. Nevertheless, as malaria and dengue are potentially deadly diseases, I thought the doctor might have a point. Better safe than sorry. Where there any studies exploring the effectiveness of natural Deet alternatives?
Conducting some online research, here's what I learned:
- According to a UK study conducted in Bolivia that compared three mosquito repellents -- one eucalyptus based, one neem based, and one mixed essential oils based -- to a repellent containing 15% Deet, the eucalyptus-based repellent gave 97% protection for four hours, whereas Deet only gave 85% protection. The study reported that the other 2 products did not provide significant protection from mosquito bites.
- A UC Chapel Hill study compared Deet to several natural repellents -- and found Deet superior to the botanicals (providing protection for 300 minutes), though one botanical gave protection for 94 minutes, the others repellents were almost useless.
- A US Department of Agriculture study compared Quwenling, lemon eucalyptus plant to Deet concluded that "as a topically applied mosquito repellent, Quwenling has a shorter duration of effectiveness than Deet."
- Another UK study compared a eucalyptus repellent to Deet and found "no significant difference between PMD (the eucalyptus-based insect repellent) and Deet in terms of efficacy and duration of protection."
On the basis of these studies, in sufficient concentration, eucalyptus insect repellents would appear to offer an effective, safe, and natural alternative to Deet.
It's worth considering that many of the natural substances are produced in countries where there is no government oversight over the processing and labeling of the natural agents. As trusted brand-names seldom offer natural product alternatives to Deet, one may have to go on faith that the bottle of “natural repellent” contains the indicated substance in the strength claimed. Sadly, when purchasing locally-produced natural products in a corruption-prone region, you can’t be so sure what you are buying.