Using the Ginseng tea, no change!

15 days ago, I decided to start a course of ginseng tea. By this I felt a little tired , and that several scientific studies praised the invigorating this root had caught my attention. But as dietary supplements are quite expensive, I opted for tea with ginseng .
After 15 days with about 2 cups daily, the result is not very convincing.
Has anyone ever tried it? Is it maybe just a matter of patience?
Anyway yesterday I found supplements rather cheap in a supermarket. So I think I'll complete with tea
capsules. And within a month it will be better ... To be continued