She has now begun sporting a moustache for charity campaign Movember, which will also help draw attention to this rare medical condition.
Sarah, said: "My cousin does it every year and I just thought 'I have a moustache, I might as well raise some money with it. Everyone I have told has been really supportive and proud of what I'm doing."
Before her diagnosis, she was unable to understand the symptoms like irregular periods and weight gain.
She said: "I might grow a fully beard, you never know! I don't know what will happen, but it should be fun. "I'm definitely nervous about going four weeks - I've never gone that long before. I can get away with it for a bit, especially at the start because I'm strawberry blonde. But the hair does grow quite thick."
She added: "It used to embarrass me a lot, and my brother even called me Mac3, after the razor.
"I didn't know what was happening to me and I was sick of people staring at me in the street. But finally enough was enough and I had to accept that it was a medical condition that was just part of me. I now realise it's nothing to be ashamed of. I want people to understand I'm not trying to be a man and that my facial hair is something that can't be helped."