Eat broccoli. That's it. And it really works.
I ate broccoli daily for years because I was afraid of getting cancer, and lo and behold, the side effect was suppressing my herpes outbreaks!
Try it. It's worth it. Just don't overcook it so you can be sure to get the nutrients from it.
There have been periods in my life where I have let the broccoli eating slide and the herpes has reappeared. I simply start up eating broccoli again and soon I am out-break free again.
Additional benefit: my sexual partners have never developed herpes.