It is supposed to be used as a treatment and preventative for the flu and H1N1.
Here is a brief explaination:
http://www.youngeagerminds.com/2009/08/influenzinum-200-homeopathic-medicine.htmlThere are good reviews on this remedy and it seems to have been out for a long time and it doesn't have mercury in it.
Also, you're not supposed to take this if you've already had the flu vaccine.