Tempestt Henderson, from Florida, eats up to five bars of soap a week and washing powder as well, the Daily Mail reported here.
According to doctors, the toxic compulsion is a rare medical condition, PICA, which causes an appetite for substances that are largely non-nutritive.
People suffering form PICA have been known to compulsively eat metal, coins, chalk, batteries and toothbrushes. It can often be caused by a mineral deficiency, which explains why pregnant women often crave eating coal when needing iron.
"In the shower, I like to lather up a green bar of soap, and lick the bubbles. And as the soap disintegrates, I pop a tiny amount of the soap into my mouth and suck it. It's heavenly," she was quoted as saying.
"I love the clean feeling it gives me. Eating soap feels so much cleaner than just washing with it."
The doctor gave Tempestt intensive Cognitive-behavioural therapy (CBT), to give her replacement thoughts that will prevent her from compulsively reaching for soap.
"I'm learning to think about positive things when I feel I need to eat soap," she said.
She has also been encouraged to go for long walks, avoiding places where soap is present, like bathrooms and laundrettes.
According to psychologists, Tempestt most likely turned to soap eating as a comforting coping mechanism when she found herself away from her family.