Sir Elton John File picture: Hugo Marie/EPA

Sir Elton John "lost [his] own humanity" because of his substance addictions, and he has admitted his life took a turn for the worst and he became a "monster" when he "hit the pinnacle" of his career.

The 70-year-old music legend has credited his successful career for opening up "imaginable doors", but has admitted when he "hit the pinnacle" his life started to go on a downward spiral and he soon became a "monster" because of his substance abuse. 

Speaking openly at Harvard University on Monday, the 'Rocket Man' hitmaker - who picked up the Peter J. Gomes Humanitarian Award from the Harvard Foundation at the bash because of his work to fight against HIV and Aids - said: "My passion and commitment to music opened up imaginable doors and took me to new heights in life. But once I hit the pinnacle, happiness became elusive and darkness crept in. 

"I lost my own humanity in an excess of drugs, alcoholism, and eating disorders. During my addictions in the 1980's the AIDS epidemic surfaced, and the government took no notice of it. 

"I lost so many friends to AIDS and I didn't put myself on the line because of the addictions I was going through. The drugs turned me into a monster."

Elton - who has sons Zachary, six, and Elijah, four, with his husband David Furnish - has been sober for almost 30 years, and he has revealed a young male battling with AIDs encouraged him to change his ways. 

He explained: "I had the luck to meet Ryan White and his family. I wanted to help them, but they ended up helping me much more. Ryan was the spark that helped me to recover from my addictions and start the AIDS foundation. Within 6 months I became sober, and clean, and have been for the last 27 years."

And now Elton is dedicated to helping others to "embrace their own humanity". 

The 'Tiny Dancer' singer continued: "Today, my mission to help other people embrace their own humanity and that of others is the most powerful and positive force in the whole wide world. Through my career and humanitarian work, I've seen how people can be pulled together. The human spirit is the most powerful thing in the world, and when it embraces kindness and does good things, wonderful things happen. 

"Nothing is more profound or powerful than recognizing our common humanity. I know how easy it is to despair. We can rise above it and lift people up.

"We can change the world, and embrace our common humanity. This period of darkness we're going through right now is the period right before the light we will all treasure.

"Only when society embraces the humanity of everyone, everywhere, will this world start to come together and to heal. Until they do, we'll be in the mess we are today."