Guernsey's health department is urging all users or former users of a controversial cancer drug GcMAF to contact their GP.
The unlicenced drug has been banned after its UK factory closed amid fears materials used aren't fit for human consumption.
Hundreds of islanders have already pleaded with politicians and health officials to have the ban lifted.
The Guernsey resident whose controversial cancer drug has been banned by island authorities has had his claims about its alleged benefits challenged on national TV.
David Noakes appeared on The One Show on BBC One, where he threatened to smash the TV camera after being interrogated in what he called "a horrible interview".
Mr Noakes was seen on TV telling his interviewer: "I think that was a horrible interview and frankly I would scrub the whole thing. I don't think you gave me a chance."
The weekend event coincides with International Pride Month and the 51st anniversary of the Stonewall riots.
The scheme has been backed by the island's Lieutenant-Governor, and is the first of its kind in the Channel Islands.
Sunny spells and isolated light showers. After dusk fair spells with isolated showers.