But the Home Alone actor seems to have turned a major corner, and is now sporting a fuller frame and healthier complexion.
The New York native, who currently works as a DJ, stepped out yesterday in New York City looking the best he has in a long time.
The allegations said he regularly shoots up heroin and the addictive painkiller oxycodone (dubbed hillbilly heroin).
The report went on to claim Macaulay had turned his Manhattan apartment into a drug den.
Although the reports were immediately denied by the star's spokesperson, Michelle Bega, his estranged father, Kit Culkin, pleaded with his son to seek help before it's too late.
The 67-year-old pensioner - who hasn't spoken to Culkin in 15 years following a row over his £11million fortune - told The Sun: 'I hope that he has the right people looking after him.'Too distraught to talk any more, Kit's wife, Jeanette, 68, explained the pair fear the former Home Alone actor is 'dying of some disease or heavily into drugs' after seeing disturbing photographs of the star.
Responding to the drug addiction allegations, Culkin's publicist Michelle Bega told MailOnline: 'The report in the National Enquirer that Macaulay Culkin is addicted to heroin and assorted hallucinogenics is not only categorically without merit, but it is also impossibly and ridiculously fictitious.'
The Enquirer claimed Culkin's alleged drug use intensified 18 months ago - around the time he split from long-term girlfriend Kunis, who is now dating Ashton Kutcher.
Two weeks ago, Macaulay was spotted out at Hollywood hot spot Chateau Marmont.
Although he wasn't as skinny as before, his appearance didn't entirely help to end the addiction rumours as he was seen clutching his stomach and appeared to be sick.
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Hopefully now the Enquirer will stop running those pics of him from February.