Dietary supplements could have unintended consequences because people who take them might believe they are healthier and therefore immune to the effects of risky behavior such as casual sex, excessive drinking and unhealthy food consumption, according to a recent study.

Researchers at Taiwan’s National Sun Yat-Sen University conducted two separate experiments, giving  150 study participants a placebo pill, with half of them believing they were taking a multivitamin.

The study, published in the journal Psychological Science, found that those who believed they had taken the vitamin expressed less of a desire to exercise and a stronger desire to take risks, such as having casual sex, drinking, sunbathing or going to wild parties.  They were also more likely to prefer a buffet meal than a healthier, organic meal.

“Because dietary supplements are perceived as conferring health advantages, use of such supplements may create an illusory sense of invulnerability that disinhibits unhealthy behaviors,” the authors wrote.

They hypothesized this series of behaviors resulted from the effects of a phenomenon called “licensing,” meaning in this case that the positive choice of taking a vitamin gave the study participants “license” to partake in pleasurable activities.

“Hence, people who rely on dietary supplements for health protection may pay a hidden price: the curse of licensed self-indulgence,” they wrote.

The use of vitamins and other dietary supplements has increased dramatically in the past decade, and the study authors believe consumers should be taught about the licensing effect in order to avoid the negative consequences of risky behaviors.