One man's belief is no substitute for a controlled clinical trial.
Especially someone who may well have been generously reimbursed - or at least got free treatment - for sharing his story, and being "an ambassador".
Apologies to Sir Ian if he hasn't. But that's how the "health industry" works, and that's how the Daily Mail works - new drugs / treatments which have yet to have full trials and peer review are 'released' via the popular press, so that the unsuspecting public break down the GP's door asking for the treatment, often with some 'star' fronting the story.
It stinks. But that's not to say Vigore is bad. It's to say "we don't yet know".
[added:] I'm no Guardian fan, but their take on the story is rather different to the Sun and the Mail