This AttackDex is for Black, White, Black 2 & White 2. If you're looking for the Generation VI Attackdex, Click here
The power stored using the move Stockpile is absorbed by the user to heal its HP. Storing more power heals more HP.
This move has four tiers of healing; 3 are stockpiled, 1 isn't. Unfortunately the one that isn't is that the attack doesn't do anything if you haven't stockpiled so you have to make sure to Stockpile first. If you use Swallow after 1 Stockpile, you will recover 1/4 of your Max HP If you use Swallow after 2 Stockpiles, you will recover 1/2 of your Max HP If you use Swallow after 3 Stockpiles, you will recover all of your Max HP