Films such as Limitless and Lucy explore the ability of certain drugs to enhance people’s cognition. In real life, however, these so-called smart pills are supported with only limited evidence that they sharpen an individual’s memory, decision-making skills and capacity for creativity.

Sold over the counter as supplements, these substances are classified as nootropics. Many of them are marketed as a blend of vitamins, minerals and ancient herbs that contain phytochemicals and antioxidants purported to improve brain function.

Some prescription stimulants are also used by perfectly healthy people who want to boost their energy and concentration. These include Vigil or Provigil (modafinil), which are used to treat sleep disorders such as narcolepsy, and Ritalin (methylphenidate) and Adderall (a combo of several amphetamine salts), which are prescribed for attention-deficit hyperactivity disorder.

But researchers are still studying whether these medications might allow people to enjoy the super-duper results some characters in the world of science fiction films have experienced.