A post circulating on social media since late June carries an alarming claim: that 'a major study involving more than 470,000 participants found that using sunscreen massively increases the risk of three major types of skin cancer' [1]. The study is real. The conclusion the post draws from it is the opposite of what its authors found [1].
The paper, published in 2023 using UK Biobank data on roughly 470,000 people, did report a correlation: people who used more sunscreen had higher rates of skin cancer [1]. Its authors flagged that result as 'paradoxical' and explained why it appears [1]. Fair-skinned and heavily sun-exposed people - those at the highest baseline risk - use the most sunscreen; many apply too little or reapply too rarely to get the protection the label promises; and a great number begin using sunscreen diligently only after a skin-cancer diagnosis [1].
That is the textbook shape of a correlation that runs backwards - an association driven by who reaches for sunscreen, not by the sunscreen itself [1]. The study's actual conclusion says as much, stressing 'the importance of adequate and frequent sunscreen use and minimization of exposure to UV light, particularly in individuals with fair skin' [1].
The dermatologist who led the work, Dr. Ivan Litvinov of McGill University, was direct when the distortion spread: 'The proper use of sunscreen, combined with other sun-protection measures, reduces the risk of skin cancer' [1].
Getting this backwards carries a real cost. The American Cancer Society projects about 112,000 new invasive melanoma diagnoses and about 8,510 melanoma deaths in the United States in 2026 - the toll that sun protection is meant to reduce [2]. A post telling people that the thing shown to lower that risk instead 'massively increases' it does not correct the science. It inverts it [1][2].
