Pippali – Long Pepper is a very unique spice. 
Piper longum medicinal Properties
Rasa (taste) – Katu (pungent)
Guna- Laghu, Teekshna (strong, piercing)
Vipaka- Madhura – Undergoes sweet taste conversion after digestion
Veerya – Ushna – Hot potency. (wet variety has cold potency)
Effect on Tridosha – Balances Vata and Kapha Doshas. (wet variety increases Kapha Dosha).
Part used- Fruit, root
In this article, only the fruit is explained. Long pepper root will be explained separately.
Dosage-
Powder 0.5-1 gram in a single or multiple doses per day, usually administered after food.
uses: 
Kapha Vataghni – Balances Kapha and Vata Dosha
Katu – Pungent taste
Ushna – hot
Vrushya – aphrodisiac
Pitta Avirodhini – Does not increase Pitta to a large extent.
Deepani – improves digestion strength
Rasayani – anti aging, rejuvenative
Anushna – not very hot
Snigdha – unctuous, oily
Rechani – causes purgation
Shwasahara – useful in asthma, COPD and other respiratory diseases
Kasahara – relieves cough, cold
Udarahara – useful in ascites
Kushtahara – useful in skin diseases
Pramehahara – useful in diabetes
Gulmahara – useful in abdominal tumor
Arshahara – relieves piles, haemorrhoids
Amanut – useful in indigestion, relieves Ama
Marutahara – Useful in Vata imbalance disorders
Pittaprakopini – slightly increases Pitta.
Kshayapaha – relieves chronic lung disorders, tuberculosis.