Therapy adherence is the extent to which a consumer persists in the behavior, such as taking medication, recommended by her physician. Failure to adhere to physician’s therapy advice contributes to disease progression and increased mortality rates, resulting in annual direct and indirect healthcare costs in excess of $177 billion in the U.S. alone. In the medical literature, scholars now see patient empowerment – increasing the involvement of the patient in therapy choice – as a key strategy to improve patient adherence. In this paper we distinguish between decisional empowerment – asking patients to choose their own therapies based on information provided by the physician – and informational empowerment – transfer of non-diagnostic health information (such as information about existing therapies or about the patient’s preferences and values) to the patient – and empirically study the effect of patient empowerment on patient adherence. We have gathered self-reported data on patient empowerment and therapy non-adherence from 11,735 patients in 17 countries on 4 continents and estimate a structural equation model with Bayesian MCMC techniques. We find that decisional empowerment consistently leads to lower therapy adherence and informational empowerment only increases therapy adherence for patients who exhibit a high level of trust and commitment towards their physician. These findings have important implications for healthcare providers, firms and public policy administrators, regarding education of medical professionals, the content of messages to patients in the media, and the design of adherence programs.