Bloodletting and spiritual power?

Is there any spiritual power in your blood? Some people say so and they recommend drinking or licking your own blood, for example when you get tattoo or even nosebleed.

Some take it more seriously and cut themselves on purpose or sacrifice animals. But i like animals, so that is out of the question.

Also, is there any benefit of using blood on skin?

In many cultures/religions blood has been seen as an ultimate sacrafice to gods. seeing as it has to do with gods I would presume it to be spiritual also your own blood would have no scientific purpose but mentally/spiritually it could hold more significance depending on the kind person you are. I believe there might be something to be obtained by drinking blood though i rather not go walking in public drinking blood