Hormonal birth control methods have become increasingly popular since 2000, as the technology becomes more convenient for users, moving from daily pills, to weekly patches, to yearly implants. Implanon is an example of a long-term birth control implant. The goal of this project is to create an accurate computational model of Implanon’s hormone diffusion over its standard prescription length: three years. Because Implanon is intended for long-term use, any potential improvements in the drug or release mechanism take several years to clinically test. It is time and cost inefficient to develop several new designs and test them all over this long time period. Instead, we can eliminate those designs that fail to reach specifications in our computer model and be more confident in the clinical success of those that function properly in our computer model, thus reducing the number of clinical trials needed and the time and money spent. We created a two-dimensional cross section model of the Implanon implant and surrounding tissue under mass transfer conditions model using COMSOL Multiphysics software. We confirmed our model’s accuracy with comparisons to published Implanon hormone release rates at six weeks, one year, two years, and three years. Our model’s hormone release rate was found to stay within a factor of 10 of the published data at all critical time periods. This data is significant in that it has the potential to expedite the hormone modification process. There were several assumptions made in the model’s schematic design as well as material properties and boundary parameters. It is recommended that more in vivo experimentation and data gathering on Implanon implant placement and hormone diffusivity be conducted to improve this model’s accuracy.