Is panax ginseng different from the Ginseng of the grocery shop?

There is something I don't understand about ginseng. By the past I bought ginseng at the grocery shop. I took pieces of ginseng, it was difficult to eat because it is spicy but I succeeded. However, I had no effect at all. I took Ginseng several times and I didn't notice any benefits. I thought that Ginseng was useless against my condition and that it did nothing against candida. Then, I ordered Panax Ginseng, and took 2 pills before dinner and then, I had a very strong candida die off during the night. Is the ginseng that we buy at the grocery shop different from what people call panax ginseng?