Potions are used to put some sort of effect on your ninja, which varies depending on the potion you choose. These range from dizziness to an anti-gravity potion - so as you can imagine there is plenty of fun to be had experimenting with them.
They also provide you with a certain amount of XP for using them, though this tends to never be comparable with any of the training regimes.
Below you will find a list of the potions available in clumsy ninja and their statistics:
Makes a ninja spin uncontrollably
Costs: 50 Coins or 4 Gems (for 5)
Earns: 10 XP
Unlocked: Level 3
Makes it hard to stay on your feet!
Costs: 100 Coins or 6 Gems
Earns: 60 XP
Unlocked: Level 7
Freezes anybody who dares to drink it!
Costs: 150 Coins or 8 Gems
Earns: 350 XP
Unlocked: Level 12
Your ninja won’t be calm after drinking this!
Costs: 250 Coins or 10 Gems
Earns: 1,000 XP
Unlocked: Level 21 (Level 8 with Gems)
Costs: 1,000 Coins or 12 Gems
Earns: 2,000 XP
Unlocked: Level 31
Costs: 2,500 Coins or 15 Gems
Earns: 2,500 XP
Unlocked: Level 46 (Level 12 with Gems)
Costs: 250,000 Coins or 30 Gems
Earns: 8,000 XP
Unlocked: Level 50 (Level 14 with Gems)
How do you combine potions?
Some of them can be combined, but others, like rage, aren't as easily combined. Freeze and tornado, for example, can be combined. Hope that helps! ;)