The existence of
pheromones in humans is controversial, partly because of definitional difficulties and partly because of the question of possible chemical substances. The synthetic compound Methyl dihydrojasmonate (
Hedione) is potent to bind to vomeronasal-type 1 receptors (VN1R1s) and activate limbic areas of the brain in a sex-specific manner. However, one of the most important definitional points for a human
pheromone effect has not yet been investigated, i.e., whether smelling
Hedione, a model of
pheromone, has a behavioral effect. We tested in females whether
Hedione leads to altered perception of male social stimuli. Each of the included women were sensitive to
Hedione and were tested around the time of ovulation in three consecutive sessions, during each they were exposed to either
Hedione or
Phenylethyl alcohol or Odorless air. We measured the speed of male face recognition (implicit priming task) and collected ratings of facial attractiveness and likeability of men (explicit task). Only about half of the women tested were sensitive to
Hedione. Those women did not show any effect of
Hedione exposure in the implicit priming task and moderate, but non-significant effects in the explicit task. We therefore assume that
Hedione is not a potent model of
pheromone in humans and this observation may be due to the fact that the artificially produced substance is not suited for signaling the proximity of other humans. Furthermore, the high rate of
Hedione-specific
anosmia leads to the hypothesis that a substantial proportion of individuals has a poor V1NR1 receptor expression.