High-quality couple relationships enhance psychological well-being and resilience against mental disorders, whereas distressed relationships contribute to emotional distress. Recently, the focus has shifted from clinical interventions for couples in crisis to relationship education programs that enhance communication skills, foster conflict-management strategies, and promote mutual commitment. Despite proven efficacy, several limitations persist: most programs target couples and their current relationships, limiting the generalizability of skills and accessibility for single individuals; theoretical frameworks lack explicit references to well-being models; many programs adopt traditional cultural orientations, overlook sexuality; and delivery remains primarily face-to-face, despite growing interest in online formats. This study presents the development of a new relationship education intervention that addresses current limitations in the field. A literature review has been conducted to analyze theoretical models, to identify the best target population, and a delivery method that guarantees scalability, accessibility, and cost-effectiveness while maintaining efficacy. As a result, "Love is not enough" has been developed. It is an online guided self-help intervention designed for individuals seeking to understand healthy relationships, enhance personal resources, improve existing relationships, or prepare for a future one. Grounded in Cognitive-Behavioral, Nonviolent Communication, and Positive Psychology models, it consists of thematic modules that combine psychoeducation, self-monitoring tools, and practical exercises. It addresses key aspects of couple life, including challenging unrealistic expectations about love, fostering self- and other-awareness, maintaining a balance between autonomy and connection, nurturing the relationship through shared goals and values, managing conflicts, enhancing communication and mutual support, and cultivating intimacy, passion, and sexuality. The program provides in-depth insights into co-parenting, rebuilding relationships after breakups, and balancing work and personal life. Moreover, participants receive support from a trained Tutor, a psychologist who fosters motivation, commitment, and goal attainment through activity monitoring and online guidance. Future steps include evaluating its feasibility and efficacy through a randomized controlled trial.