Your doctor should have told you more about the medication. First of all it has been out for a number of years. Second it is a well tolerated drug. Having said that, no drug including over the counter drugs such as aspirin and Tylenol are completely benign.
Your doctor can send your for a screening liver function test and again at 6 weeks later. If you go on the website www.lamisil.com you can get more information.
As far as natural remedies, I am not aware of any that are successful. There are many anecdotal reports. If there was something that worked great, the drug companies would figure out a way to market it and charge more.
You should discuss this further with your doctor and make your decision based on information.
Hope this helps.