The Advertising Standards Authority (ASA)
The Advertising Standards Authority (ASA) remit now extends to cover companies' own marketing claims including websites.
For further guidance and copy advice visit www.copyadvice.org.uk or if you have a specific question email advice@cap.org.uk. There is also an AdviceOnline database to sign-up to, which is free service.
The following link lists a number of therapies and advice on what is acceptable http://www.copyadvice.org.uk/Ad-Advice/Advice-Online-Database/Advice-Online-Index.aspx#T