cosmetic surgery increases the likelihood of individuals indicating that they would undergo a cosmetic procedure (Brown et al. 2007) and patients who have undergone cosmetic procedures consistently report knowing someone who has had cosmetic surgery (Javo and Sørlie 2010; Solvi et al. 2010). Furthermore, the media has a well-documented influence on desire for cosmetic surgery. Sociocultural theory suggests that people learn beauty standards within the social and cultural context (Thompson et al. 1999). People judge their own appearance based on the beauty standards defined by the society in which they live. The media is one channel through which messages about beauty ideals are portrayed (Cafri et al. 2005) and has an effect on how women perceive themselves and thus whether they engage in appearance-changing strategies. For example, greater psychological investment in physical appearance and greater internalisation of mass media messages of beauty are found to predict more favourable attitudes towards cosmetic surgery (Sarwer et al. 2005). Similarly, media (cosmetic surgery-related and appearance- related television programmes and cosmetic surgery adverts) and peer influence (friend conversations about appearance) predict attitudes towards cosmetic surgery. Specifically, a higher amount of media exposure and friend conservations correlates with more positive attitudes towards cosmetic surgery (Sharp et al. 2014). This suggests that traditional forms of media such as television programmes about cosmetic surgery are a motivating factor in women undergoing cosmetic surgery. Whilst the role of cosmetic programmes, magazines and advertisements have been investigated as potential influencing factors for consideration of cosmetic surgery, less research has investigated the role of social media, particularly newer forms such as Instagram, on desire for cosmetic surgery. Also, most studies to date have been correlational in nature (e.g., Sarwer et al. 2005; Soest et al. 2006; Markey and Markey 2009; Swami 2009; Furnham and Levitas 2012; Sharp et al. 2014), with not much experimental research being carried out. Further, research has historically focused on attitudes (positive/negative) towards cosmetic surgery, which whilst being influential in deciding behaviour, do not necessarily indicate actual behaviour. Hence, the current study intends to fill this gap by examining the effect of Instagram on desire for cosmetic surgery. It aims to examine whether exposure to young women with facial cosmetic enhancements causes participants to consider undergoing cosmetic surgery, hypothesising that viewing images of females who have undergone cosmetic surgery (compared to a control condition) will lead participants to have an increased desire for cosmetic surgery. A potential model explaining the effect of social media use (e.g. Instagram) on the desire for cosmetic surgery points toward the mediating role of body dissatisfaction. Studies have found that social media use can impact desire for cosmetic surgery (American Academy of Facial Plastic and Reconstructive Surgery 2013; De Vries et al. 2014). Therefore, we hypothesise that those who use social media more will show a higher desire for cosmetic surgery than those who use it less. Additionally, body dissatisfaction has been found to influence attitudes towards cosmetic surgery (Lee et al. 2009; Markey and Markey 2009). Thus, it is hypothesised that those who have lower appearance satisfaction will have a higher desire for cosmetic surgery than those who are more satisfied with their appearance. Also, social media use has been found to negatively affect body Curr Psychol satisfaction (Brown and Tiggemann 2016; Holland and Tiggemann 2016). It may be that social media use influences body dissatisfaction, which in turn leads to an increased desire for cosmetic surgery. This study aims to test this mediation model as a mechanism for how social media affects desire for cosmetic surgery among young women. Method Participants and Design The study employed a between-subjects design with two levels of the independent variable: cosmetic enhancement condition and travel image condition. An a priori power analysis using G*Power (Faul et al. 2007) indicated that 51 participants were needed in each condition to have 80% power for detecting a medium sized effect (d = 0.5), when employing a 0.05 criterion of statistical significance. We intentionally oversampled in a single wave of data collection via social media, survey distribution websites and the undergraduate psychology programme of a state university in the UK. 118 women aged 18–29 years (Mage = 20.71 years, SD = 2.53) took part in this study. Most of the participants had been a resident in the UK/US for several years, comprising young professionals or university students. They represented a diverse ethnic group (50.9% White, 25.3% Asian, 10.1% Black, 13.5% Other). Only 4 participants (3.4%) had previously undergone a cosmetic procedure (facial filler, Botox, microdermabrasion and scar retouching). Participants were randomly allocated to one of the two conditions, resulting in 59 people in the cosmetic enhancement condition and 59 people in the travel image condition (control group). Ethical approval for the present study was granted by the Department of Psychology Ethics