You can make the ester-c, emergen-c, type of stuff yourself for 1/1000th of the cost. I was buying the boxes for awhile but it gets expensive, especially as vitamin C has a half life of 4 hours so you need to keep taking it throughout the day. Places like Kwan-jai.com recommend 1000 mg's every hour for illness and such things..
puritan.com is a GREAT way to get pure ascorbic acid crystals for CHEAP. They have a 3 for 1 sale right now and they ship internationally as far as I've been told.
One of the factors of how well it is absorbed is the buffering agent, it's pH and such things. That is why places like Kwan-jai.com recommend the baking soda mixture. The sodium bicarbonate buffers the acidic vitamin C powder to the body can absorb it better.
The recipe kwan-jai recommends is 1 heaping teaspoon of vitamin c crystals mixed with 1/2 teaspoon of baking soda in an 8 oz glass of water. You can slowly build up to every 4 hours if needed, but I just do it in the morning upon waking and at night before bed.
I also take the bicarbolife pills from alkalife.com in the morning with food and evening. (and L-Lysine of course)
Have you tested your pH yet? Good health food stores should sell the paper. It's a good way to get a general idea of where your body's pH is at.
Everyone is different of course, but in the same light, everyone I have advised (a handful) has had positive results regarding herpes after increasing the pH of their body.
A great starter book is: The Acid-Alkaline Balance Diet.