Sexual health risk-taking behaviour is typically initiated during adolescence and continues throughout teenage years and early adulthood at higher levels than at other life stages. For some groups (e.g. deprived and vulnerable populations) the risks can be greater still. Risk behaviours in early youth are related to increased rates of risk-taking and the adoption of multiple risk behaviours in early adulthood. Prevention interventions implemented early on are shown to be most effective at preventing or reducing the poor health outcomes associated with risk-behaviours. Policies and prevention interventions are informed by current data showing patterns of risk behaviour, identification of emerging behaviour, factors associated with these behaviours and evidence of intervention prevention effectiveness.This submission presents a linking commentary which summarises and critiques a series of peer reviewed publications, supported by additional publications, all of which were carried out during my employment at Liverpool John Moores University. Studies have identified key factors affecting sexual development and associated behaviour; associations between sexual and other behaviours, such as alcohol behaviours; and the relationship between social and well-being factors and sexual behaviours in adolescents and young people. Studies also evaluate public health initiatives and review public health evidence of intervention effectiveness. These studies have contributed to understanding sexual development and its impact on behaviours during the life course; have highlighted the health service and education needs of young people; and have identified effective interventions and intervention components to inform national guidance, public health policy and intervention development