Is Lady Gaga dying?
Halperin, who has written explosive biographies about Angelina Jolie and Michael Jackson, looks at the woman behind the outrageous persona.
"How sick is Lady Gaga?" asked INSIDE EDITION's Diane McInerney.
"She has a mild bout with lupus, it's not too severe. She's definitely not dying," said Halperin.
In an exclusive interview Halperin told INSIDE EDITION about Gaga's secrets he unearthed for his yet untitled book, due out next winter.
"What is Lady Gaga's biggest secret?" asked McInerney.
"I think Lady Gaga's biggest secret is her insecurities. She's extremely insecure about her appearance, and that's why she'll never go out in public unless her nails are properly put on, all the make up, the wig," said Halperin.
"What are Gaga's obsessive rituals to maintain her weight?" asked McInerney.
"Lady Gaga is very obsessed about her weight. She stares obsessively at her body in a mirror every day, and if there is a bit of a weight gain, she takes action. She really reduces her diets, a lot of the time just goes on liquid diet," said Halperin.
In spite of all her success, Halperin says there is still one thing the 25-year-old pop diva longs for.
"What is Lady Gaga's biggest desire?" asked McInerney.