There are 19 defined potion effects in Minecraft. Two are given by Player actions, Two more by food items, One by a Cave Spider 's attack, Six others work but aren't used yet, and Eight have no effect.
Potion effects are given two parameters on creation: Duration (in ticks) and strength.
ID
Name
Effect
Strength
How it's acquired
1
potion.moveSpeed
Expands FOV and increases walking speed
Increases both effects, stronger levels turn the FOV upside down and reverse controls
Sprinting
2
potion.moveSlowdown
Contracts FOV and decreases walking speed
Increases both effects, reversing controls if very strong
Charging a Bow
3
potion.digSpeed
Arm swings faster, blocks break faster
Increases both effects, arm motion appears to stop if very strong
4
potion.digSlowDown
Arm swings slower, blocks break slower, however it is still possible to break blocks just as fast with insta-break on
Increases both effects
5
potion.damageBoost
No apparent effect
6
potion.heal
Instant health gain
Sets the amount gained
7
potion.harm
Instant health loss
Sets the amount lost
None, but death reason is reported as "was killed by magic.".
8
potion.jump
No apparent effect
9
potion.confusion
Causes the view to wobble similarly to using a portal
No apparent effect
10
potion.regeneration
Causes health to regenerate over time
Makes health regenerate faster
Eat a Golden Apple
11
potion.resistance
No apparent effect
12
potion.fireResistance
No apparent effect
13
potion.waterBreathing
Causes air meter to be constantly full while underwater
No apparent effect
14
potion.invisibility
No apparent effect
15
potion.blindness
No apparent effect
16
potion.nightVision
No apparent effect
17
potion.hunger
Causes food meter to deplete faster
Increases the depletion rate
Chance on eating raw/rotten food.
18
potion.weakness
No apparent effect
19
potion.poison
Deals damage over time
Increases the damage rate
Given by a Cave Spider 's attack.