Join Our Studies – Chapel Hill & North Carolina Click the icons below to take the survey to see if you’re eligible! You can take the survey for as many studies as you’d like. We will contact you for more information if you are eligible. Help us test our new app for PrEP for youth ages 18-29 and earn up to $340. Help test two sexual health mobile apps meant to increase HIV testing and PrEP uptake for gay and bisexual men ages 15-29. Test technology to support sexual health and earn up to $275! Test a new website for youth with HIV and earn up to $345.