Evan Reas is a former Googler and co-founder of a local social-network startup called Circle, and he has found an innovative way to be an efficient entrepreneur.

Reas told Business Insider that taking mushrooms is the unconventional method he uses to brainstorm and evaluate his creative decisions.

“It completely changes how you think,” Reas told Business Insider. “About your problems, about yourself, everything. It forced me to ask, ‘Is what I’m doing important?'”

Mushrooms are illegal in the United States and contain the psychedelic drug psilocybin. But entrepreneurs like Reas probably wouldn’t make the conscious decision to take a damaging drug if it affected his work ethic negatively.

A study conducted by John Hopkins University of Medicine found that mushrooms have more of long-lasting positive effect on the user than negative, enhancing feelings and aesthetic sensibilities. The study found that a single dose of psilocybin could have positive effects for up to a year.

Psilocybin can facilitate experiences that change how people perceive themselves and their environment,” said Roland Griffiths, a study author and professor of psychiatry and behavioral science at Johns Hopkins. “That’s unprecedented.”

Circle keeps users informed of when  friends and networks are nearby and has received $6 million in funding from investors such as Andreessen Horowitz, Ashton Kutcher, and Scott Weiss. It currently has a user base of 4.5 million.