Stephanie left her home in Uphall, at 2 pm on Monday. Stephanie went missing after spending Monday afternoon with a 16-year-old female friend in Livingston. She is white, 5 ft 2in, of stocky build with blonde, shoulder-length hair. She was last seen wearing a pink hooded top with the brand name Lonsdale on the inside of the hood, black combat trousers and black boots.
According to the police she requires regular injections of insulin and went missing with medication, sufficient enough only to last until yesterday.
A police spokesman said: 'Stephanie normally deals with her condition in a proper manner. However, her failure to return home last night, and her medication running out today, suggests she may seek help from elsewhere or she could be ill.'
He also added 'The public should be aware that diabetics without insulin can show signs similar to that of someone under the influence of drugs or alcohol.'
'This would be a clear sign that Stephanie requires urgent medical treatment.'