Zamorak potion

The Zamorak potion is a powerful potion

Background
The Zamorak potion comes in 4 doses. The whole potion increases strength by 10, attack by 5, and doubles your max hit. The boosts will stay for 5 minutes and then drop by 1 level per minute. When used with the Saradomin Potion, it makes the utimate warrior. Jagex knew such an item would be popular and made its G.E. price 10k. Rich players though were able to buy lots of them. This item is also popular in pvp worlds. People could make money by buying a Zamorak potion for 10k and selling it for 20k. People will pay outrageous prices for this potion. This potion can also be made at 95 Herblore.

Trivia
Because of this potion, people stopped buying strength potions and super strength potions. Thus their prices dropped dramaticaly. Since it could sometimes take lots of waiting to but the potion, smart people bought strenght potions.