Background: Therapeutic adherence (TA) aims to improve the health of individuals and populations. It is highly complex and influenced by multiple factors. Non-adherence rates are still excessively high, and it is important to know more about them to intervene. Objectives: To analyze concepts of TA, reflect on factors associated with TA, systematize intervention strategies, and understand assessment methods. Main topics under analysis: As part of patient behavior, TA is the expected outcome of health professionals' recommendations/prescriptions, following mutual cooperation. Patient motivation is essential to overcome barriers to behavioral change, and patients are considered co-responsible for their treatment. Health professionals adopt TA promotion strategies to benefit and mobilize users. Health services and policies support the minimization of obstacles and encourage the evaluation of TA to improve practices. Conclusion: TA is multifactorial, which makes the process more difficult. Successful TA requires coordinating all involved stakeholders -users, health professionals, and social and political bodies, by anticipating the appropriate measures.