Adolescent sexual health education in Western Kenyan secondary schools has seen policy changes aimed at reducing abstinence rates. The study employed a mixed-methods approach, including pre- and post-intervention surveys and qualitative interviews with educators. Prevalence rates showed a significant decrease in reported sexual activity from baseline (p < 0.05) but varied by school type. While overall abstinence increased, specific themes such as curriculum content and teacher engagement influenced outcomes. Further research should focus on long-term effects and sustainability of the implemented policies. Adolescent sexual health, secondary schools, policy changes, abstinence rates Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.