Why do my painkillers seem to work better when taken with my multivitamins with ginseng?

I am in alot of pain with my back and take painkillers first thing in a mornin as I can hardly walk. They seem to work better and faster when taken with the ginseng multivitamin why is this??|||Placebo effect. There is no way ginseng is causing painkillers to break down and absorb into your system faster. I have heard ginseng said to have some pain relieving properties, but whatever amount is in your vitamins is almost certainly a trace amount and certainly not enough to cause any clinical effect. However, I personally swear by several different supplements/herbs that I cannot find any explanation for, you just have to do what works for you.|||You have a vitamin deficency.