Passion flower is commonly sold as a tea in in powdered form inside capsule. The recommended daily dosage is 400 mg once daily. Most capsules are sold in 200 or 400mg sizes. If you are brewing loose tea approximately 2 to 4 grams will have a similar effect.
Passion flow is a sedative and it can be combined with other similar herbs to increase the effect, Kava Kava seems to work extremely well when combined with passionflower.
Passion flower does not have any associate negative side effects.