Fitspiration, or imagery of thin muscular individuals that displays their physiques while posing or exercising, is a popular type of content on Instagram which ostensibly exists to encourage individuals to engage in a healthy lifestyle. A subtype of fitspiration imagery, “transformation” imagery, depicts physical changes following a “lifestyle change” involving diet and exercise. Despite its intentions, fitspiration imagery largely promotes one idealized body type (the fit ideal) and can be accompanied by messages encouraging restrained eating. Viewing fitspiration imagery has been associated with body dissatisfaction and appearance comparison in women, but the impact of transformation imagery specifically on women's body image has not yet been studied, nor has the impact of the broader fitspiration category and the transformation subtype on women's body image been compared. The current study aimed to clarify the relations between fitspiration and transformation imagery, appearance comparison, and body satisfaction using an experimental design. Female participants (N = 161) completed a measure of body satisfaction and then were randomly assigned to view one of three types of images: fit ideal only, body transformation, or travel (control). Participants then completed measures of appearance comparison and body satisfaction. Viewing fit ideal only and body transformation imagery was associated with lower body satisfaction and higher appearance comparison. The relation between image type and changes in body satisfaction was mediated by appearance comparison. Findings suggest that individuals may benefit from limiting exposure to fit ideal and body transformation imagery, particularly if they are vulnerable to engaging in appearance comparison.