Why have certain ingredients used in tobacco products been banned?

Because it makes the person who is using the drug have all types of problems with there body.

There are eight major endocrine glands, each with a different function: pituitary gland: the “brain” of the endocrine system; regulates all seven of the other glands and secretes growth hormone.thyroid: regulates a person’s metabolic rate, which is the amount of energy expended daily by a person at rest.thymus: assists in the development of a person’s immune system.adrenal gland: regulates fluid and sodium balance within the body, and secretes epinephrine (“adrenaline”) when the body is under stress, producing the fight-or-flight response.ovaries (in females) and testes (in males): control the development of secondary sex characteristics.pancreatic islets: regulate blood sugar.pineal gland: regulates biorhythms and mood, and stimulates the onset of puberty.