What's a better pre workout supplement, something with yohimbine?

Watch out!: Yohimbine is a medication that produces vasodilatation. The fda aproved its use for impotence but not as a pre-workout supplement. Anyway, there are so many otc products stating that they have yohimbine, but they don't require (for now) fda aproval. The best supplement for pre-workout is a combination of carbohydrates and proteins taken anytime between 30 minutes to 2 hours before exercise.