A recent investigation by Which? has identified a budget-friendly insect repellent that offers superior protection against mosquitoes compared to some higher-priced alternatives. A £4 bottle of Asda's Extra Strength Insect Repellent spray provided 9.5 hours of complete protection, outperforming many more expensive products.
The findings come amid warnings from experts about a potential increase in mosquito populations due to recent hot and humid weather in Britain, making insect repellents a growing concern for outdoor activities.
Which? tested 12 different insect repellent products. Volunteers were exposed to mosquitoes in a controlled environment to determine the duration of protection. Two products, Pestects Mosquito Repellent Bracelets (£19.99 for 12) and Meadows Organic Citronella Spray (£6 per 100ml), performed poorly, offering protection for less than three minutes or even being bitten almost immediately.
In contrast, the Asda spray, costing £4 for a 125ml bottle, demonstrated impressive effectiveness, matching the performance of brands costing more than double its price. Natalie Hitchins, Which? Head of Home Products and Services, stated that consumers do not need to spend a premium for reliable protection, highlighting that the £4 supermarket spray significantly outperformed pricier options.
Several other products also provided complete protection for the full 9.5-hour test, although none were as cost-effective as the Asda option. These included DEET-based repellents such as Jungle Formula Maximum Aerosol Insect Repellent (£7.20), Boots Repel Maximum DEET & PMD Aerosol (£9.10), Pyramid Trek 50 (£9.50), and Lifesystems Expedition Max DEET Mosquito Repellent (£9). These DEET products are considered highly effective, with DEET being widely regarded as a gold standard for repelling insects by confusing their senses.
Autan Insect Repellent (£5.65), containing 20% picaridin, also delivered strong, 9.5-hour protection. Picaridin is a synthetic compound that masks the scent of humans to insects. Incognito Insect Repellent Pump-Spray (£13.99), utilizing plant-derived PMD from lemon eucalyptus extract, provided nine hours of protection and is suitable for use on babies from six months old.
Boots Soltan Soothe & Moisturise Aftersun Lotion with Insect Repellent offered 4.5 hours of protection, suitable for shorter durations. Which? emphasized that effective repellents typically contain scientifically proven active ingredients such as DEET, icaridin, PMD, or IR3535, rather than relying on less effective natural oils like citronella or peppermint.
DEET is recommended for high-risk areas for mosquito-borne diseases, while icaridin is considered a strong alternative. PMD, derived from lemon eucalyptus, is effective when formulated correctly, but Which? cautioned against confusing it with less effective citronella or eucalyptus oils. IR3535 is deemed suitable for lower-risk regions.
The consumer group also stressed the importance of correct application, advising users to cover all exposed skin thoroughly and apply repellent after sunscreen. For facial application, it is recommended to spray into hands first in a well-ventilated area before rubbing onto the face, followed by washing palms.