Are you interested in a non-hormonal (copper) IUD? Do you have regular menstrual cycles (periods)? Stanford University OB/GYN researchers are seeking individuals who are interested in participating in a study evaluating a new copper IUD that may have less side effects than the copper IUD that is currently prescribed. There is no cost to participate. Participants are followed for up to 5 years. Participants will be compensated for their time. To qualify potential participants must: - Be age 35 or younger - Have regular menstrual cycles - Be sexually active with a male partner who has not had a vasectomy See if you qualify here: https://redcap.stanford.edu/surveys/?s=3AYDEE34JP For more information, please contact our research team. For participant's rights questions, contact 1-800-860-2906