Natsal, the National Surveys of Sexual Attitudes and Lifestyles, is a pioneering initiative conducted in the UK since 1990, supported by the Wellcome Trust and other esteemed organizations. As one of the largest surveys of sexual behavior globally, Natsal aims to explore and document sexual attitudes, lifestyles, and health across different generations. With a robust methodology that includes face-to-face interviews and self-completion sections, the surveys have engaged over 45,000 participants to ensure representative data from the British population.

Over its four iterations—Natsal-1, Natsal-2, Natsal-3, and the upcoming Natsal-4—this research program has addressed critical public health issues, including STIs and sexual health education, significantly shaping health policies and strategies in the UK. Natsal's impact is evident in its role in informing programs like the National Chlamydia Screening Programme and sexual health education initiatives. As society continues to evolve, Natsal-4 will capture contemporary sexual lifestyles, ensuring that public health strategies remain relevant and effective.