The hip-hop star went on a liquid-only diet and worked out for three hours a day to achieve the staggering weight loss, reported Daily Mail online.
A gaunt-looking 50 Cent shows off the effects of his weight loss in a photo on his official website.
He is due to play a cancer-stricken American football player in a forthcoming film and wanted to look authentic for the part.
In the past 50 cent has made much of his muscular body, often appearing topless in videos and showing off his huge frame.
The 34-year-old is starring and co-producing Things Fall Apart, which will also feature Ray Liotta and is directed by Mario van Peebles.
Soon after the dramatic weight loss pictures were posted on his website, 50cent.com, rumours swept the Internet they were a hoax.
But in a statement the star, real name Curtis Jackson, confirmed the pictures were authentic.
"I was starving but I've been eating. I'll be back in shape in no time," said the rapper.
In addition, 50 Cent had the tattoos on his arms removed in preparation for his acting career."I took'em off. I've been on a few acting projects and they been making me get up My call time is four hours before the regular acting talent because of the tattoos," he said.
But 50 Cent's achievement still does not top that of Christian Bale, who lost 63lbs for his role in the dark mystery film The Machinist.
Bale went from 185lbs to 122lbs to look like he 'had not slept for a year' and did it by cutting out most foods and relentlessly exercising.