Social media advertising is a great marketing tool for attracting consumers in this digital era. In a preliminary survey done, an interesting phenomenon was discovered where young generations, particularly Generation Y and Generation Z, showed a lack of motivation to purchase fashion products from Instagram social media platform after the pandemic Covid-19. Therefore, further investigation on the relationship of young consumers to purchase intention on fashion products from Instagram social media platform needs to be conducted. The research includes three independent variables Irritability, Informativeness and Entertainment that influence Online Purchase Intention and are mediated by Advertisement Value and Attitude towards Advertisement. Non-Probability Purposive Sampling is used to process 282 respondents using a Partial Least Square – Structural Equation Modelling (PLS-SEM) with software SmartPLS 4. Findings show that informativeness and entertainment do not positively influence Instagram’s advertisement value, while irritability negatively influences advertisement value. Advertisement value does not positively influence online purchase intention and attitude towards advertisement does not mediate relationship between advertisement value and online purchase intention. Managerial implications highlight the importance of avoiding irritability in advertisement value to increase the intention to purchase.