Why is a Repellent Effective?
Insect repellents are effective because they discourage mosquitoes from landing on, climbing on or biting skin.
In general, according to the U.S. Centers for Disease Control and Prevention, "higher concentrations of active ingredient [found in personal repellents] provide longer duration of protection, regardless of the active ingredient." However, a higher concentration of active ingredient does not mean the product will better repel mosquitoes.
If traveling, make sure you purchase personal repellents. These products can be found in drug stores, supermarkets and hardware stores or online. When purchasing repellents, always look for the active ingredient concentrations suitable for your activity and apply or use the product as directed by the manufacturer.