does the clear pill exists?

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I watched a movie called "Limitless" just now, starring Bradley Cooper and Robert De Niro. My attention was caught by this clear pill called NZT. It unlocks your full potential and lets you utilize your brain 100%. They even have a website that clearly discuss about the pill. But I read somewhere that it's just a fictional pill and website is just a promotional scheme for the movie itself. Do you have any ideas about this?