Q. What’s the deal with the blood bond? Why do some people go crazy
when they drink the blood of drained vampires? Why doesn’t Sookie get
high when she takes blood from Bill or Eric?
A. Here goes: everything’s variable when it comes to vampire blood
being ingested by humans. There is no formula that says, for example,
that 2 ounces of vamp blood will make every blood junkie go nuts.
Vampire blood is like any other street drug in that respect. The
variables include the age of the blood (how long it’s been out of the
vampire), the age of the vampire, and the mental condition and
previous drug use of the imbiber. Blood taken straight from the
vampire does not necessarily make the drinker high, unless he or she
is already an addict. A blood bond may be formed when a vampire and a
human exchange blood, though often it takes more than once. It also
may depend on the emotional bond existing between them.
Then you have this side of the argument. But beware this is just fans being fans.
This wikia article is a little TMI, so beware.
If vampire blood is consumed by a human (or any other creature) in small dose (one or two drops), it will heighten the senses, increase strength, make an intense sexual experience, and cause hallucinations. The effects are different with each person; however, if the blood is taken in a large dose, it causes several different effects, such as healing someone who has injuries, even if they are dangerously close to death, and metaphysically or spiritually bond the drinker with the vampire in question. If taken in a large dose when there is no injury on the human, they will have an extremely increased libido.