Hello dear and welcome to the medhelp forum. Niacin is usually prescribed for increasing the levels of HDL or the good cholesterol. It helps in protecting against the effects of atherosclerosis. It is available in many forms, fast acting and long lasting, over the counter and prescribed. There is a known incidence of facial flush with high doses. It could also cause headaches, dizziness and raised blood sugar. It is therefore prudent to take it under a physician’s prescription and supervision. Withdrawal has not been reported with stopping though gradually reducing and then stopping the supplementation is advised. Wishing you all the best.
Timed-release niacin is commonly prescribed to prevent arterioschlerosis. It acts as a mild vasodilator, relaxing the blood vessels and improving the microcirculation. The "fast-acting" niacin causing flushing of the face and sometimes itching. There should be no problems whatsoever with discontinuing niacin "cold-turkey" , nor should there be any withdrawal symptoms.