How can you stop time? You can stop time by feeling content. The more you strip away your worries and your desires, the slower time seems to move. This could be one of the reasons that time felt as if it moved slowly when we were younger.
Contentment alone is enough
Indeed, the bliss of eternity can be found in your contentment - Tao Te Ching, verse 46
When you get there, the world already seems like a better place. No drugs necessary.