OBJECTIVES: Turkish healthcare system has developed in terms of quality, access, equity and efficiency with the introduction of a number of reforms under “Health Transformation Program” since 2003. However, these have created significant financial burden to the government. In order to contain expenditures, avoid overuse, misuse and abuse; government has implemented certain cost sharing tools. Our objective is to define how co-payment mechanism has affected patients’ purchasing behavior regarding OTC-type products. METHODS: Regulations and reports published by Ministry of Health and Social Security Institution, “Health Systems in Transition Turkey 2011” and “IMS Market Prognosis 2012-2016” reports are examined. RESULTS: In Turkey, family physicians do not act like gatekeepers since a formal referral system does not exist. Therefore, patients could directly apply to secondary/tertiary healthcare services without co-pay. At secondary/tertiary healthcare levels, co-payment rate is 5 TL and 12 TL for outpatient care in public and private hospitals respectively, 3 TL for prescription fee and extra 1 TL for each product exceeding 3 products per prescription. All active workers pay 20% while retirees pay 10% of total amount of the prescriptions as co-pay. Patients with chronic conditions requiring medical report are exempt from co-pay. Considering different co-payment rates and number of visits/prescriptions recorded in hospitals, it is calculated that patients paid approximately 3 billion TL in total outpatient care as co-payment in 2012. CONCLUSIONS: Minimum 9 TL in total is required as a co-payment for outpatient care and prescription, if patient visits a public hospital. Therefore, for products with a lower price than 10 TL, patients rather go directly to pharmacies. This behavioral change of out-of-pocket payments might be explained by improved purchasing power and increased co-pay rates.