Advertisement of medical products on social media has become increasingly common, and is associated with increased online shopping in pursuit of self-medication. Such practice highlights the influence of social media advertising on individual use of medicinal products without consultation with health care professionals. Objectives: To better understand the practice of online self-medication and investigate its prevalence in Palestine, this study specifically assessed the probable reasons, extent of use, and source of advice for online self-medication among university students in Palestine. In addition, the study evaluated factors that influence online self-medication in this population, such as gender, age, knowledge in medical specialty, and perception of online products. Methods: This study was conducted using a "paper pretested questionnaire" prepared in the Arabic language and self-administered to 700 students from three public universities in Palestine (Al-Najah, Al-Quds, and Bethlehem Universities). The study was conducted over three months (Nov. 2019 – Jan. 2020) and included university students of all years from both medical and nonmedical faculties. Data were collected, coded, entered, analyzed, and summarized using Statistical Package for Social Sciences version 25. Descriptive results were expressed as frequency, percentage, and mean±SD. Results: Female (87.6%), younger (20-29 years), and medical (57.4%) students tended to use online self-medication more than their peers. Respondents practiced online self-medication to save time (50.4%) and money (49.8%), and a majority (65.7%) reported using online products without consulting physician or pharmacist. Nearly a third of respondents (29.6%) reported that they did not have any instructions on how to use products, and a significant number experienced side effects from the products they used (p-value <0.001). The internet was the most commonly reported source for self-medication (45.3%), particularly sponsored advertising campaigns on websites (16.7%). In terms of product type, skin care products (76.7%) were the most commonly used, followed by hair products (72.2%), and vitamins (58.8%). In addition, cream and ointments were the most frequently used dosage forms (71.3%). The majority of respondents (64.1%) described their experience as “bad” and “not healthy”; half (50.9%) reported having side-effects and a third (33.6%) stopped using the products because of side effects. Statistical analysis showed that the difference in usage between genders was significant for vitamins, traditional herbs, weight loss products, hair products, skin products, nail products, and food supplements (p-value <0.05). In addition, the relation between specialty domain and product use was significant for hair products, food supplements, traditional herbs, and herbal mixtures (p-value <0.05). The relationship between reading information and experiencing side effects was significant with a p-value of 0.000. Finally, the relationship between side effects and product re-use was significant (p-value <0.05) Conclusions: Online self-medication is a common practice of young Palestinian university students; this constitutes a health problem, and intervention is needed to minimize risk. We emphasize the important role of health care professionals in educating the community, especially the youth (<30 years), regarding online medication practices that may have harmful side effects.