Trained young people to serve as online peer influencers to the participants. The online peer influencers were young people who would be considered peers or contemporaries of the study participants, similar in age, gender, and country. Similar to the online marketers, the online peer influencers were trained by RAES to ensure the information shared through their personal experiences was correct and accurate as it related to the content themes of preventing early pregnancy, contraceptive knowledge and use, community norms, and services. Study participants did not know the peer influencers personally.

Marketing influencers were individuals who had a network of followers on social media and were regarded as digital opinion leaders with significant social influence on their network of followers. We trained these influencers and worked closely with them to develop and share SRH information that highlighted the content themes of preventing early pregnancy, contraceptive knowledge and use, community norms, and available online services.

Combined health education content from the peer role model arm and the marketing influencer arm.

Study content for the 2-week Facebook-based intervention was developed by West African non-governmental organization, Réseau Africain de l'Éducation pour la Santé (RAES), or African Network for Health Education in English. RAES created culturally relevant SRH information tailored to the target population of young adults, taking the form of educational materials and personal stories and building off of their social communication campaign that promotes health and social change, entitled C'est la Vie! (CLV). Content themes centered around preventing early pregnancy, contraceptive knowledge and use, community norms pertaining to sexual and reproductive health, and available online services. All content was in French.

A 12-item knowledge score taken from the Phase 8 version of the Demographic and Health Surveys Program woman's questionnaire. Participants answer Yes or No to if they know 12 common contraceptive methods. Scores range from 0-12 with 12 indicating higher knowledge.

3 item scale adapted from the Contraceptive Self-Efficacy among women in sub-Saharan Africa (CSESSA), a scale found to be reliable among population samples in sub-Saharan Africa. Scales range from 0 (not at all confident) to 10 (completely confident).

3-item scale. Participants are asked if they are aware of three specific providers that provide online services throughout West African mentioned in the study content. Scores ranged from 0 (unaware of any service providers) to 3 (aware of all three service providers).

6-item scale. Participants are asked to self-report if they used any of six online services that were highlighted in the study content, including using websites for advice, using a chat-bot, and communicating with organizations through WhatsApp. Scores range from 0 (no services used) to 6 (six services used).