From the Guidelines
Both DEET and picaridin are effective insect repellents, but the choice between them should be based on personal preference, specific needs, and consideration of their safety profiles, as both are considered safe for human use when applied as directed 1. In terms of efficacy, DEET provides protection against a wider range of insects for a longer duration, typically 6-8 hours for concentrations of 20-30% 1. Picaridin is nearly as effective, especially against mosquitoes, and offers 4-8 hours of protection at 20% concentration. Some key points to consider when choosing between DEET and picaridin include:
- Concentration: Products with 20%–30% DEET are considered optimal for protection against most tick species, while picaridin at concentrations >15% can repel as well as DEET when applied to skin 1.
- Safety: Both DEET and picaridin are considered safe for human use when applied as directed, but DEET can cause skin irritation in some people and may damage certain synthetic fabrics, whereas picaridin has shown a good safety profile with fewer skin irritation reports and no damage to fabrics.
- Duration of protection: DEET typically provides 6-8 hours of protection, while picaridin offers 4-8 hours of protection. For most adults, a product containing 20-30% DEET or 20% picaridin is recommended for optimal protection, applying to exposed skin and clothing, avoiding eyes, mouth, and hands of young children, and reapplying as needed, especially after swimming or sweating 1. The most recent guidelines recommend using either DEET, picaridin, or other repellents for the prevention of tick bites, with a strong recommendation and moderate-quality evidence 1. Some key considerations for specific populations include:
- Children: Products with lower concentrations (10-20%) are advised, and should not be used on infants under 2 months old.
- Sensitive skin: Picaridin could be more suitable for everyday use or for those with sensitive skin.
- Longer outdoor activities or high-risk areas: DEET might be preferred for longer outdoor activities or in areas with a higher risk of insect-borne diseases.
From the Research
Comparative Efficacy of DEET and Picaridin
- The efficacy of DEET and picaridin as insect repellents has been compared in several studies 2, 3, 4, 5.
- A review of laboratory and field tests found that picaridin provided similar or superior protection to DEET against mosquitoes, with some evidence suggesting that picaridin had a longer duration of action 2.
- A field trial in northern Australia found that 19.2% picaridin provided >94.7% protection for at least 9 hours, while 35% DEET provided >95% protection for 7 hours 3.
- Another study found that picaridin 20% performed equally well as DEET 20% in providing protection against mosquito bites, including arbovirus and malaria vectors 4.
Safety and Duration of Protection
- The duration of protection provided by DEET and picaridin can vary depending on the concentration and formulation of the repellent 2, 3, 4.
- A study found that DEET maintained 100% protection throughout the testing period of up to 1 hour, while picaridin provided >95% protection for 8 hours 3.
- Another study found that picaridin 20% provided excellent protection up to five hours after application, with a overall five hour protection rate of 97.4% 4.
Repellent Sensitivity and Vector Species
- The efficacy of DEET and picaridin can vary depending on the vector species, with some species being more difficult to repel than others 4, 5.
- A study found that picaridin performed better against Mansonia and Culex spp. than against Aedes and Anopheles spp. 4.
- Another study found that DEET at concentrations of 20% or more provided the best efficacy against Aedes mosquitoes, while Citriodora repellency was lower compared to other products 5.