<p>Previous studies have found that androstadienone (AND) influences women’s mate preferences and their attractiveness ratings of men. This study examined whether AND affects women’s engagement in intrasexual competition (i.e., the likelihood of gossip) and intrasexual competition-related perceptions (i.e., perceptions of flirtatiousness from romantic rivals). Overall, 52 women participated in a double-blind, placebo-controlled, and within-subject experiment, where they were randomly assigned to receive the AND or placebo on two consecutive experimental days. After the AND or placebo was administered, participants completed an information-sharing task and a first-impression task in the context of intrasexual competition to assess women’s self-reported likelihood of gossip and perceptions of flirtatiousness of romantic rivals, respectively. The results indicated that AND increased the self-reported likelihood of negative gossip in women. However, the influence of AND on the self-reported likelihood of neutral and positive gossip in women was not significant. In addition, AND increased women’s perceptions of flirtatiousness from romantic rivals. These findings indicate that AND may intensify women’s intrasexual competition and perceived romantic threat in the context of intrasexual competition.</p>