A grandmother, who is facing drug dealing charges, sampled a pudding laced with cannabis outside the gates of Downing Street on Wednesday.
Mrs Tabram says the drug is more effective than NHS medication.
Patricia Tabram, from Northumberland, also delivered a letter to the prime minister, asking for the drug to be legalised on medical grounds.
Mrs Tabram, 66, of Humshaugh near Hexham, admitted possessing cannabis with intent to supply in January.
She says she uses the drug to ease health problems.
The widow, who cooks up cannabis-laced treats for neighbours and friends in her village, was also meeting a literary agent to discuss publishing a book she has written, and the possibility of making a film about her life.
In the letter to Mr Blair, she claims commercially-produced medicines often make her ill, and are more harmful than cannabis.
She says her dependence on the NHS has lessened since she started taking the Class C drug to help her with symptoms of depression, whiplash back pain and tinnitus.
Mrs Tabram, who was not allowed into Downing Street because she had not made an appointment, said: "The cannabis masks the pain. It is a herb and I want people to call it a herb. It is no different to sage, thyme or rosemary.
"It makes me feel pleasant. It takes away the feeling of despair and makes me feel optimistic about life instead of pessimistic."
She says the number of people in her cannabis-eating club, who also use the drug for medicinal reasons, had recently jumped from 17 to 138.
Northumbria Police twice raided Mrs Tabram's bungalow in May and June 2004, and seized 32 cannabis plants.