In addition to his music career, Sixx is also a best-selling author and has released three autobiographies: The Heroin Diaries: A Year in the Life of a Shattered Rock Star (2007), This is Gonna Hurt: Music, Photography, and Life through the Distorted Lens of Nikki Six (2013), and The First 21: How I Became Nikki Sixx (2021).
Sixx, who struggled with addiction in his younger years and was once declared clinically dead after an overdose in 1987, celebrated his 22nd year of sobriety last year.
His estimated net worth is a hefty $45 million (£35.7m), with some sources suggesting his fortune might actually be closer to $65 million (£51.6m).