I completed the Companions Questline and I got a power to transform my self into a werewolf. One of the disadvantages is that you aren't able to use your inventory or cast spells. Because of that, the only way I heal my self is using potion from my inventory and using a healing spell. When I have these disadvantages, is there a way to heal yourself when transformed?
While in Werewolf form the only way to heal yourself apart from waiting is to feed on downed enemies by interacting with the bodies, this will also increase your transformation time.
Initially you can only feed on humanoid bodies but the "Savage Feeding" perk available with the Dawnguard DLC allows this be expanded to any non-undead corpse albeit with smaller amounts of restored health.