Niacin is a blanket term that refers to nicotinic acid or any of its derivatives. Niacin, otherwise known as vitamin B3, is water-soluble and found in many foods, such as vegetables, milk, and fish, as well as several supplements. There are three main forms of niacin available in over-the-counter as well as prescription products: Nicotinic acid, nicotinamide, and inositol hexaniacinate. Although they are entirely different forms and perform differently in regards to lowering cholesterol, they are often packaged as “niacin.” Therefore, when looking for a niacin product to lower your cholesterol, you really need to read labels in order to determine exactly what you are getting.
Nicotinic AcidNicotinic acid is the most extensively studied agent and has been found to lower cholesterol levels as well as prevent cardiovascular disease. In fact, nicotinic acid affects all aspects of your lipid profile by lowering LDL cholesterol by 15 to 25 percent, lowering triglycerides by 20 to 50 percent, and raising HDL cholesterol by 15 to 30 percent. Despite its ability to greatly lower cholesterol, nicotinic acid is also associated with some undesirable side effects, such as flushing, itching, gastrointestinal upset, and hot flashes. The side effects from nicotinic acid can be so troublesome that many discontinue taking it.
Because of these side effects, other forms of nicotinic acid have been manufactured and include extended-release (ER) and sustained-release (SR) preparations. These forms are designed to be released into the blood over an extended amount of time and alleviate side effects. Although these preparations do reduce flushing, some of them can produce a side effect that is even worse –- liver failure. The extended-release product Niaspan has not been associated with liver failure, but it is only available through prescription.
NicotinamideNicotinamide is an amide derivative of nicotinic acid. This derivative of nicotinic acid has been used to prevent the flushing experienced from taking the nicotinic acid formulations of niacin. There are very little studies that examine nicotinamide’s ability to lower cholesterol, and the current studies out there suggest that nicotinamide does not lower cholesterol. This can be confusing because both nicotinic acid and nicotinamide are often labeled the as “niacin.”
Inositol HexaniacinateInositol hexaniacinate is often referred to as “flush-free” or “no-flush” niacin. It is a modification of nicotinic acid that was specifically designed to alleviate the side effects associated with niacin use. Although it is advertised to lower cholesterol levels, there are very few studies out there about inositol hexaniacinate that support this. Additionally, these formulations are often more expensive than their nicotinic acid counterparts. So, while you are paying to avoid flushing and hot flashes, you may be missing a big benefit -- lowering your cholesterol and your risk for heart disease.
Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (PDF), July 2004, The National Institutes of Heath: The National Heart, Lung, and Blood Institute.
Meyers CD, Carr MC, Park S, and Brunzell JD. Varying cost and free nicotinic acid content on over-the-counter niacin preparations for dyslipidemia. Ann Intern Med 2003;139:996-1002.