In 2x09 - Party Guessed, Derek was put into physical contact with the corpse of Peter Hale as well as the light of the full moon in a ritual conducted by a possessed Lydia Martin. Peter's corpse began to reanimate, gripping Derek's arm drawing his blood. Derek's eyes flashed red, his alpha spark being activated and the power being transferred to Peter's corpse. In minutes, Peter was completely revived. In the aftermath, Derek was left weak for several hours.
In 3x11 - Alpha Pact, Derek uses his pain siphoning on a sick and dying Cora Hale with maximum impact. The process relieves Cora of her pain, part of Derek's alpha spark was transferred to Cora, augmenting her healing factor and she eventually heals completely of her sickness. On the negative side, Derek was rendered unconscious from the strain and his alpha status was lost.