iSupport-Portugal is an eHealth program for informal dementia caregivers, adapted from the World Health Organization's original. Internationally, this version stands out as the only one enhanced to be exploited as a data collection tool for researching dementia care dyads. This paper outlines the multistep methodological approach employed to harness iSupport-Portugal for research purposes. The platform's adoption is depicted by characterizing its early users through sociodemographic and health data collected via self-administered forms in their accounts. Eligible participants are Portuguese unpaid caregivers supporting a community-dwelling person with dementia (PwD). In the initial six months of the public launch, 365 users registered on iSupport-Portugal, 52.3% as caregivers and 44.7% as health/social care professionals. Caregivers were predominantly highly educated (M 15.3 years), employed (64.3%), supporting a parent (70.5%), and exhibited significant psychological distress, with 70.5% scoring symptoms of anxiety, depression, or both. iSupport-Portugal has attracted early attention from caregivers, particularly among newer generations. Challenges in leveraging iSupport-Portugal for research are discussed, and ongoing research is presented, featuring a proof-of-concept prospective cohort study that examines iSupport's predictive ability for PwD institutionalization. Tools to collect data on dementia care dyads in a cost-effective manner are valuable for planning specialized healthcare services and policies.