Gender inequity is a pervasive challenge to health equity on a global scale. Over the last two decades gender has been increasingly recognized by the global community as a social determinant of health. Significant gender differences have been reported worldwide regarding the use of alcohol, prescription drugs and illicit substances, and women who use substances are underrepresented in treatment services. Although gender-responsive treatment can contribute to improved treatment outcomes for women who use substances, there is a paucity of treatment services that are specifically focusing on or that are explicitly sensitive to the needs of women. To facilitate the recovery of women who use substances, this PhD study aims to gain insight in the critical ingredients for gender-responsive treatment for women. First, a qualitative study (in-depth interviews) among women who use substances (N=60) was applied to explore the perceived treatment barriers, facilitators and needs of women. Next, an exploratory study (4 focus groups) of service providers' perspectives on the continuum of gender-responsive interventions was conducted to explore in-depth how treatment can be made more sensitive to treatment needs of women. Third, a multiple case study (in-depth interviews, participant observation) has been set up to gain insights into how Trauma Center Trauma-Sensitive Yoga (TCTSY) can be implemented in treatment, and what are the perceived experiences of TCTSY in addiction recovery.