Apply SPF 50+ sunscreen daily to the face, neck, décolleté, and hands, using the two-finger rule, to prevent skin aging, dark spots, and skin cancers.

noli's read

Daily use of sunscreen is widely supported by dermatological research to prevent damage caused by UV rays. Meta-analyses and randomized controlled trials (RCTs) confirm that UV exposure is the primary environmental factor in premature skin aging (photoaging) and skin carcinomas. The 'two-finger' claim is a rule of thumb often recommended by experts to ensure the application of the optimal dose of 2 mg/cm², which is necessary to achieve the SPF rating indicated on the product. However, applying this amount to such a large area (face, neck, décolleté, AND hands) may be considered insufficient in practice to guarantee total coverage in accordance with laboratory tests. While the advice is scientifically sound in principle, the precision regarding dose distribution is a compromise between theoretical efficacy and realistic daily usage.

the sources

1. 1Green AC, Williams GM, Logan V, Strutton GM 2011
2. 2Hughes MCB, Williams GM, Baker P, Green AC 2013