The 43-year-old supermodel said in her struggle to end smoking, she found out that it was easier to quit alcohol than cigarettes, reported Daily Mirror.
"People told me that cigarettes are harder to quit than alcohol. I didn't believe it, but you know what? It is harder," Campbell said.
"I'm not someone who wants to light up inside people's homes, including my own, and I don't want to stand outside on street corners anymore," she added.
The supermodel said even though she is determined to quit her habit, the thought of smoking still makes her desperate for a cigarette.
"I have more energy and I have more fun than when I was drinking and I can hang out really late and get up early in the morning with no hangovers and still smile," she added.