Introduction Contraceptive knowledge mediates access and use. We aimed to assess whether an online educational video describing all methods and their benefits, side effects and mode of action increased young women’s contraceptive knowledge and their long-acting reversible contraception (LARC) preference and uptake.

Method We used Facebook advertising to recruit young women aged 16–25 years. Participants completed the pre-video survey (S1), watched the 11-min video, then completed surveys immediately after (S2) and 6 months later (S3). Outcomes were analysed using McNemar tests and multivariate logistic regression (generalised estimating equations).

Results A total of 322 participants watched the video, completed S1 and S2, and 88% of those completed S3. At S1 only 6% rated their knowledge about every method as high. Knowledge improved at S2 for all methods (OR 10.0, 95% CI 5.9 to 17.1) and LARC (OR 4.2, 95% CI 3.1 to 5.7). LARC preference increased at S2 (OR 1.7, 95% CI 1.4 to 2.1) and S3 (OR 1.4, 95% CI 1.2 to 1.7), as did LARC uptake at S3 (OR 1.3, 95% CI 1.11 to 1.5). LARC uptake was driven by a 4.3% (n=12) absolute increase in intrauterine device (IUD) use, but there was no change in contraceptive implant use (p=0.8). The use of non-prescription methods such as condoms and withdrawal did not change (OR 0.92, 95% CI 0.76 to 1.11).

Conclusions Many young women in Australia do not feel well informed about their contraceptive options. The contraceptive education video, delivered via social media, increased their self-reported contraceptive knowledge and IUD preference immediately after viewing, and their IUD uptake 6 months later. Focus should be given to how young women navigate contraceptive access after internet-based education, and strategies to increase access to preferred methods.