This dissertation investigates two distinct but interrelated phenomena of user innovation and user co-creation in a healthcare context. We explore the role of patients (end users of healthcare products and services) as both co-creators in the pharmaceutical and medical technology industries and their role as patient (user) innovators. To do this, we utilize both qualitative and quantitative research methods. This dissertation is divided into six chapters. Chapter 1 introduces the topic of the PhD dissertation. In Chapter 2 we discuss the theoretical background, identify research gaps, and present the specific research objectives and methodologies that will be addressed in the articles that constitute chapters 3, 4, and 5. Chapters 3, 4, and 5 present the three papers. Chapter 6 concludes on the overarching theme and provides an integrated discussion of theoretical contributions, managerial implications, limitations, and future research opportunities examined in the articles that compose chapters 3, 4, and 5. In Chapter 3, we examine ethical challenges that arise during the co-creation process analyzed through 42 semi-structured interviews with both patient co-creators and managers with long-term co-creation industry experience. Co-creation can be defined as “an active, dynamic, and social process based on interactions and relationships between firms and external stakeholders, oriented toward new product generation”. However, ethical challenges arise when firms engage in co-creation with external stakeholders. We focus on the pharmaceutical and medical technology industries as these industries have been slower in adopting co-creation practices than other sectors, mainly due to stricter legal and compliance regulations. Based on our data analysis, we develop a framework that characterizes the ethical challenges posed by co-creation, proposing an extension to Schwarz's universal moral standards for corporate codes of ethics, with additional moral standards emerging as relevant for co-creation: equality, inclusivity, and diversity. Furthermore, by exploring both patients and managerial perspectives, we reveal the discrepancies in the expectations between patients and managers. The findings are followed by recommendations to address these challenges. In Chapter 4 and Chapter 5, we study the factors influencing patients' intention to innovate and their willingness to share innovations. Patients and their non-professional caregivers, as end users of healthcare products and services, invent valuable solutions to improve their own and their communities’ health. Their main motivation for doing this is not for profit, but to address their own unmet needs and the needs of their close networks, reflecting the fact that this represents a social processe. Based on data collected by surveying more than 300 patients living with a chronic disease accessed through patient organizations and social media communities, we study patient innovators' social consciousness on their intention to innovate. Additionally, we explore the moderating effects of patients' ahead-of-trend behavior and treatment burden on the relationship between socially conscious behavior and intention to innovate. The findings confirm the positive impact of patients’ socially conscious behavior on their intention to innovate. Moreover, the fact that patients are ahead of trend strengthens the relationship between their social consciousness and intention to innovate. Even though this research does not find evidence that supports the moderating effect of burden of treatment, it does show the importance of considering burden of treatment as a factor influencing intention to innovate, suggesting the need for future research. Social welfare benefits from user innovation can only be achieved when valuable user-developed innovations are shared with others who can benefit from them. Therefore, the willingness to share user innovations becomes a relevant factor to investigate. To explore the impact of innovation-related resources (technical expertise and community-based resources) on users’ willingness to share innovations, we analyze data collected by surveying 318 chronic disease patients through various patient organizations and patient communities on social media. The study also explores the moderating effect of legal barriers on the relationship between innovation-related resources and users' willingness to share. Our empirical findings support the following hypotheses: firstly, that technical expertise and community-based resources positively influence users' willingness to share innovations; secondly, that legal barriers weaken the positive effect of community-based resources on willingness to share. Our study lays the groundwork for further research on the impact of legal barriers on user innovation diffusion. The insights gained from this study are valuable for advancing the field of user innovation as well as for manufacturers and policymakers seeking to leverage user-developed innovations.