Before making it to the big screen, Zach Braff was smoking weed and riding drunk in the back of vans with his fellow fraternity brothers.

The star who got his big break on “Scrubs” spoke Wednesday about everything from an on-screen make-out session with Natalie Portman, which he called “wonderful,” to a run around Paris looking for morning-after birth control pills for a recent hook-up.

The writer-actor-director of “Garden State,” who was a member of Phi Kappa Psi at Northwestern University, joined roughly 1,000 students in Lisner Auditorium. The event, hosted by the Interfraternity Council, Panhellenic Association and Multicultural Greek Council, cost $20,000, IFC chair Casey Wood said.

Within minutes of arriving on stage, Braff had flashed his chest, sung songs, and cracked jokes that made the GW administrator sharing the stage with him cringe.

Braff instructed the moderator, Vice President for External Relations Lorraine Voles, to put on “earmuffs” each time he joked about sex and drugs on college campuses.

The 38-year-old, who graduated with a degree in film in 1997, said he first bonded with his fraternity brothers in Phi Kappa Psi because “they smoked a shitload of weed.”

Initially hesitant about joining Greek life, Braff said soon after rushing, he had already dated a sorority girl, rode in the back of a moving van and bonded with his pledge brothers while the upperclassmen hazed them.

“As fucked up as it was, we really did bond. But I’m sure they don’t have that here,” Braff said, prompting laughter in the crowd.

Braff also recounted losing his virginity, calling it “more of a short story than a novel” because of his lack of experience.

He also talked about a pregnancy scare after having sex on a train in Europe, and the struggle to obtain a morning-after pill from a French pharmacist.

“There has been an accident,” Braff said he scribbled on a note, written with help from a friend whose French was out-of-practice. “The baby of my lover is inside of me. I do not want it there.”

He arrived on the Lisner stage after raising more than $1 million in a 12-hour period for his next movie – half the total goal. The funds, raised through the crowdfunding site Kickstarter, will go toward his next movie, “Wish I Was Here,” which will follow the tone and style of “Garden State.”

Braff called crowdsourcing a “new frontier for filmmakers who won’t get help from studios to make money.” He said he plans to start production this summer.

Braff also told the crowd that he wanted to “impart some knowledge on you and not just make weed jokes.”

He explained that the opportunity to star in “Scrubs” only came about because he was turned down for a role in a New York City play.

“At times when you don’t get that huge job or you don’t get into that thing that you wanted to get into, in my experience, something ten times more amazing has been the result,” Braff said.

Correction appended

This article was updated April 26, 2013 to reflect the following:
Due to an editing error, a caption that did not match the photo was uploaded. We regret this error.