Nonadherence to medication is a major overlooked public health issue. This commentary focuses on ways to improve medication adherence and originates from a lecture given at the 24th annual meeting of the International Society for Patient Adherence (ESPACOMP) in November 2020 to celebrate the John Urquhart prize. The content of the conference was based on 28 years of both research and clinical activities focusing on medication adherence. Medication adherence is characterized as a 3-phased behaviour: initiation, implementation, ** This term is a different construct than implementation science. Therefore, it will be written in italics in the entire manuscript. and persistence.1 Between 15 and 25% of chronic patients do not initiate their prescribed medication, and 20–40% of patients having initiated their medication do not implement it appropriately into their daily routine (e.g., omission and adapted dosing).2 Finally, premature discontinuation of medication is common and of great concern as described in real-world observational studies of a wide range of chronic diseases.3, 4 Nonadherence to evidence-based drug therapy increases morbi-mortality5 and healthcare costs6 and creates pressure on environmental footprints.7 Medication adherence is a dynamic health behaviour affected by a plurality of factors, which can be addressed via well-designed interventions. Clinical guidelines from medical societies such as the European AIDS Clinical Society or the European Society of Hypertension and Cardiology posit medication adherence as a key determinant of treatment success, which needs to be addressed by interprofessional teams. However, despite the extensive research conducted over the last 20 years in the area of medication adherence, the transfer of knowledge into practice to support patient self-management has been slow. Adherence can be envisioned as a collaborative effort involving two main participants: the patient and an interprofessional team. If the patient is the sole actor, the risk of adherence failure is higher. If the patient and team work together to build adherence, the chances of a robust foundation and implementation increases as does the chance of long-term persistence.8 Medication adherence is one of the most sensitive health behaviours to address in the relation between patients and healthcare providers (HCPs). Both patients and HCPs feel embarrassed to discuss patient suboptimal adherence. HCPs are afraid to intrude the privacy of patients and rarely directly address the issue until other aspects of patient care have been fully pursued, including additional investigations and maximum escalation of treatments. Nonadherent or partially adherent patients are usually embarrassed, fear disapproval and judgment from HCPs and when talking about their behaviour, often describe an aspired or socially desirable behaviour rather than their actual behaviour.9 Based on their fundamental right to self-determination and autonomy, patients make decisions based on their own perspectives, priorities and common sense, using various professional and lay sources of information. Specifically, patients self-regulate their medication in many circumstances and in many ways, especially if they perceive their medication to be ineffective, useless, inadequate, dangerous, addictive, too expensive or complex, having too many side effects, or simply to test if they still need it. They regulate their medication adherence by balancing the perceived threat of their condition on the one hand and their perceived vulnerability on the other hand. Bypassing the patient's perspectives is no longer an option, highlighting the need for a partnership between patient and HCPs.10 It means giving patients an active role to foster self-efficacy and helping to bridge lay and scientific knowledge. Partnership with patients along the medication adherence journey means navigating at the patient's pace. It implies allowing or helping patients to make gradual sense of their prescribed treatments and to develop medication adherence skills. Respect and trust between patients and HCPs are essential first to build adherence preventively and second to increase the opportunity to address nonadherence in a timely manner whenever it happens during initiation, implementation or persistence. The concept of “patient-as-partner” is a new paradigm that represents a change in the posture of both patients and the HCPs.11, 12 Hence, knowing that patients will not be judged but instead thanked if they report nonadherence will increase the chances of a safe and constructive interpersonal collaboration. The patient has the right to know that it might not be easy to initiate a medication, to take it on a daily basis, or to keep taking it in the long run. It might sometimes become a personal daily struggle according to other priorities. In response to such challenges, defined learning steps will reinforce acceptance, understanding and ritualization of medication management. Patients should also be aware that nonadherence relapses belong to the natural learning process. Acknowledging and understanding patients' difficulties, and giving positive feedback on patient's efforts, even if small, is the HCPs responsibility. Building an adherent behaviour is a journey—sometimes complex, often emotional—that the patient and family should not undertake alone but in a team to align the emotional perspectives of the user with the cognitive ones of the prescriber and dispenser. Supporting medication adherence over time cannot be performed by a single provider but is rather the result of an interprofessional team. We know what affects medication adherence at the patient level. What is less known is that the healthcare system directly contributes to nonadherence through identified missed decisional milestones, such as lack of explanation on the prescription and shared decision making, dose escalation or polypharmacy as response to medication nonadherence, multi-prescribers, conflicting information between HCPs, or lack of interest/time/professional structured knowledge about medication adherence. The journey between patients and HCPs might suffer from an unfavourable environment and the risk of leaving nonadherent patients on the side of the road and loosing track is high. How to slow down the speed of the journey to define directions and give patients the opportunity to be better equipped with skills and tools? Nonadherent patients should be offered a temporary authentic shelter to strengthen commitment to initiate, maintain or adjust their behaviour. Such a shelter can be rooted in short and repeated motivational interviews over time. Importantly, patients encounter not one but several HCPs—physicians, pharmacists, nurses—throughout their medication journey. This represents a significant opportunity to facilitate and address medication adherence with the right patient, in the right place, at the right time, which means that everyone's role must be defined from an interprofessional perspective. With nonadherent resistant patients, team members might be more efficient by taking turns supporting them. Agreed leadership is consensually assigned to one professional, this assignment may evolve over time and followers echo the leader's message to reinforce patient's navigation. In 2010, WHO defined interprofessional collaboration as a “Collaborative practice in health-care that occurs when multiple health workers from different professional backgrounds provide comprehensive services by working with patients, their families, carers and communities to deliver the highest quality of care across settings.” Constitutive ingredients of interprofessional collaborations are a shared team's collaborative mental model, shared and monitored perspectives, mutual credibility and trust, clear identification of roles and responsibilities, proactive communication, face-to-face meetings to discuss difficult cases and mutual support for a climate of assistance. Rather than being at the centre of attention, patients are full members of the interprofessional team. Not to forget, shared technology—electronic health records and apps to support adherence—may facilitate the blossom of such interprofessional ingredients. Development of the interprofessional practice should be rooted in pregraduate schools and then reinforced by shared collaborative guidelines to support medication adherence at the national and international levels, alongside clinical practice guidelines. More is known than ever about medication adherence, its determinants and its consequences—it is time to leverage this knowledge to make significant changes in the healthcare systems. Yet, so far, most healthcare systems have shown inertia and unresponsiveness towards the epidemic of non-adherence: no methodology, too few consensus, guidelines and policies. How long will modern healthcare systems keep ignoring the deleterious impact of nonadherence, hence decreasing efficiency, security of primary and secondary care and increasing their environmental footprints? Medication adherence is the responsibility of healthcare systems, involving policy makers, healthcare organizations and interprofessional teams. It is critical to identify how to optimally implement behavioural interventions alongside clinical investigations and prescriptions. As projects and initiatives flourish, it is time for more coordination, strong implementation and monitoring at local, national and international levels (e.g., European Network to Advance Best Practices and Technology on Medication Adherence [ENABLE] COST Action). Although interprofessional collaborations first developed in hospitals where HCPs work together in teams, this postural concept is now expanding in the outpatient care setting with distant teams. An example is the interprofessional, disease-agnostic medication adherence program (IMAP) that has been developed in an academic outpatient context between physicians, pharmacists and nurses.13 HCPs evaluate patient's acceptance of the diagnosis at initiation, often an emotional—sometimes traumatic—event, as well as the patient's readiness to start the treatment. During the implementation phase, HCPs acknowledge the patient's ownership of the treatment and the ongoing development of instrumental patient skills to reinforce ritualization of the treatment according to daily life activities (Figure 1). To support long-term persistence, HCPs and patients need to develop relationships based on mutual trust and long-term follow-up The IMAP program capitalizes on the partnership between patients and interprofessional teams8 while drawing on evidence-based practice in clinical pharmacology. Let us keep developing such medication adherence support programs! The authors have no conflict of interest to disclose.