Health Potion is a consumableitem in League of Legends. Consuming a Health Potion will restore 150 health over 15 seconds after being used. It is a very useful item for nearly every champion early game due to its affordability but loses its effectiveness as champions' levels increase. The maximum health will be too substantial for it to be significant and any damage received would be too great.
It used to be highly recommended to buy multiple Health Potions when jungling as it provided increased early-game survivability. The % health gain from jungling creeps reduces their utility.
You can use multiple Health Potions while you have one active which will queue them up to be used after the previous completes (maximum 5 stacks).
You cannot have more than 5 health potions in your inventory at a time.
Using a Health Potion, as with all other activated items (with the exception of Entropy), does not interrupt channelling. This is particularly useful if jungling as Fiddlesticks, as it will not interrupt Drain. It also won't interrupt Recall or point-capturing in Dominion.
Health Potion and Mana Potion are currently two of the cheapest items in League of Legends.
When used Health Potion gives an additional 10 health regen/second for 15 seconds, which can be improved by Spirit Visage, resulting in 12 health regen/second or a total amount of 180 health restored (as compared to 150).
If you have a charge of Crystalline Flask being used, you cannot use either a health or mana potion at the same time - the game won't proc both regen effects.
If you're having trouble sustaining in lane, usually either top or mid as AD, do not rush Vampiric Scepter - at 800 gold and only 8% lifesteal, given low (sub 150) total AD values, you usually won't be able to sustain enough from trading and lane minions. Note that 800 gold is 22.857 health potions - or 3300 total health from regen. Consider either Doran's Blades or Health Potions.
During seasonal events, the Health Potion has been replaced by seasonal items with the same effect, but different names/pictures.