Laura Plummer, 34, was sentenced to three years in prison on Boxing Day last year after she was found to be carrying 290 Tramadol tablets in her suitcase.
The shop worker had hoped Egypt’s appeal court would accept she had no way of knowing the pills were illegal in the country, but judges in Cairo upheld her conviction and jail term, The Sun reported.
Ms Plummer told the paper: “I thought the appeal judges would see sense and realise I couldn’t have known the tablets were banned. It’s just so absurd.”
The Briton was arrested at the airport on October 9 last year when she flew into the Red Sea resort of Hurghada.
She claimed she was taking the tablets - which are legal in the UK but banned in Egypt - for her Egyptian partner Omar Caboo, who suffers from severe back pain, and had no idea what she was doing was wrong.
The appeal court ruled ignorance of the law was not a defence and said the original court’s decision was correct, The Sun said.
Ms Plummer’s mother Roberta Synclair told the paper: “We’re disappointed, but not surprised. Each time we come to Egypt we prepare for the worst.”