Hitler is believed to have followed medical advice when he decided how to kill himself. Because some people have survived suicide attempts by pistol shot to the head, Hitler's doctor advised him to take potassium cyanide just before pulling the trigger. This would make death a certainty, yet would be a "manly" way to die.
Hitler distrusted the suicide capsules he was given, so he had his German shepherd dog "Blondi" killed with one of the poison capsules as a test.
Hitler died with his new wife Eva Braun. Both had suicide capsules and pistols (Hitler used a 7.65mm Walther PPK), but Eva Braun died of poison only, she didn't shoot herself. All the bunker witnesses agree that Hitler shot himself once in the right temple (not in the mouth) the bullet exiting through the top of his head. Eva was found dead beside him with no wound, but there was a strong odor of almonds in the room, the characteristic smell of potassium cyanide. Eva's pistol was unfired.