In my opinion, it's, at best, a placebo. It looks like they have their share of questionable reviews.One answers site had a reply to someone asking about it:
"It contains a number of different ingredients which have been tested as treatments for herpes simplex infections.
None of the ingredients have been clearly demonstrated as effective for people with this condition in properly conducted clinical studies. At best, the evidence of effectiveness for any ingredient is Category C, which means "Unclear scientific evidence for this use".
The herpaflor website appears to make statements in breach of US law and the laws of a number of other countries concerning untrue or unproven therapeutic claims, such as "Guaranteed to work faster and better than anything you can buy, prescription or non-prescription."
Personally, I wouldn't bother with this product until they can provide more convincing evidence of its usefulness in treating herpes simplex infections or outbreaks in actual people."
"Do the Right Thing. It will gratify some people and astound the rest." - Paraphrased from Mark Twain