How does pot affect human health?  Is it not used by only by long haired easy living "hippies" that got lost in a 1960's fueled world?  How can it have any medical value?  The secret is that POT has a bunch of chemicals in it, working together to attack cancer cells and aid in numbing inflamed nerve endings among the mixture of a hundred + more chemicals mainly contributing to human wellness..  THC is the part that makes you "happy" and reduces feelings of depression by attaching to the Cannaboid receptors in the brain in all of earth's natural creatures.  Mixed in with the THC is a chemical called CBD. 

Cancer Cells do not die, that is how they form Tumors.  They grow unchallenged by the fate that cells face when their life cycle normally ends.  CBD's attach themselves to Cancer cells and apparently has the ability to turn on the "switch" in the cell that allows it to die, therefore stopping the uncontrolled growth .  For persons with other conditions (MS, Lupus, Chronic pain Syndrome, Aids, etc...), this CBD also is what numbs the nerves that are inflamed, thereby reducing pain up to 80 percent. in a large percent of patients.

The whole marijuana plant is best for any patient vs artificial THC pills.  The method of ingestion (smoking, vaporizing and eating) all lead to different effects on the body.  OD is not possible.  if you are using it for a medical use, it would be best to seek a product high in this chemical.  A wizened grower will be concerned about CBD levels in the quality weed they distribute, and a reputable medically aware dealer would be able to supply one high in this naturally occurring chemical.

YOUTUBE:  CPMCRI's Dr. Sean McAllister - THC and CBD