Garner stars opposite Matthew McConaughey in the film. She plays an immunologist who realizes she needs to help challenge the conventional medical system in order to bring attention to HIV and AIDS.
"This was the beginning of questioning medicine, of patients questioning medicine and forcing doctors to look at it differently. Because of that, huge strides were made with breast cancer and with cancers in general and all kinds of diseases, and it all kind of dates back to this time period," said Garner.
McConaughey plays Ron Woodruff, a man who is diagnosed with the AIDS virus and given 30 days to live. He questions everything and fights conventional wisdom about treatments for the disease. His research helped many.
"Making your life mean something kind of strengthens your will to live, and that is really all we have," said Garner.
Jared Leto also stars in the film. To play men battling AIDS, both he and McConaughey underwent startling physical transformations.
"I was so taken aback the first time I saw him that I had to go into another room and kind of collect myself, but that didn't go away. I felt that way every single day. He started losing weight months before we started filming the movie, but it sped up as the movie went on. He was expending so much energy and only taking in 700 calories a day," said Garner. "And Jared just stopped eating, so Jared just changed from the first day that we shot to the end of the movie to the point where you thought he's going to fall over. But yes every single day I found it jarring and upsetting." "I feel like their performances so outshine what they did physically; it's so much more about just what they bring to the character," said Garner.
The film opens Friday. The title "Dallas Buyers Club" refers to a way Woodruff was able to work around the "system" and get non-FDA-approved supplements and medicines to others fighting AIDS and HIV. He sold memberships to his club. Those members were then provided with these alternative treatments.