The question has come up a few times lately about straight niacin (nicotinic acid) vs. slow release niacin, or inositol hexanicotinate (IHN). Some claim that there is conclusive evidence that IHN does not work at all for managing lipids. Well, that's not really the case.
Straight niacin is less expensive than IHN and has been the subject of a lot of very impressive research on lipid management. In some circles it is considered the gold standard, in fact, for cholesterol management, and is declared the treatment of choice for reducing blood lipids by the Expert Panel of the National Cholesterol Education Program (NCEP).
However, the beef against niacin is that some people flush with it. I am one of those people, and let me tell you, a strong niacin flush is NO FUN! The "flush" is a burning, tingling sensation on the skin that is due to a temporary increase in prostaglandins leading to cutaneous vasodilation when too much is taken too soon. The flush is very temporary, but WOW! It can be very uncomfortable for some people who are sensitive to it. And some people like myself can't seem to get to the point where they eventually don't flush when using nicotinic acid.
Enter, then IHN, which does not reach maximum serum levels for 10 hours after ingestion and has practically zero flushing potential.
There is indeed some evidence that IHN has very little impact on overall cholesterol or LDL/HDL ratios. That evidence is by no means conclusive, however, especially when you compare it to the evidence showing that it does have benefit. (There is also "evidence" that fish oil and herbs have no benefit, after all, so...)
IHN consists of six molecules of niacin and one molecule of inositol. It is metabolized in the body into its component parts, allowing for the positive benefits associated with high doses of niacin without the many side effects. When administered orally, IHN results in a sustained increase in serum levels of free niacin and, in human studies, is better tolerated than regular niacin.
Studies showing that IHN improves lipid profiles date as far back as the early 1960s.1,2,3 An in vitro study showed that IHN was more effective than niacin in reducing hypercholesterolemia.4 When given to rabbits on a fatty diet, IHN resulted in normalization of all lipid fractions, including cholesterol.5 In humans, IHN has been shown by two research groups to produce a reduction in cholesterol that was even more profound than that produced by niacin.1
I have worked with practitioners for over two decades now who have used IHN extensively in their practices and have the lab results to prove that it does indeed work for many people. It might not be a 100% effective, but neither is straight niacin, and neither are statins.
Niacin supports healthy blood lipid levels via its inhibition of catecholamine stimulated lipolysis in adipose tissue, its affect on hepatic lipoprotein synthesis, and its support of healthy high-density lipoprotein levels. So whether by nicotinic acid or by IHN, niacin appears to be a great option in the battle against cardiovascular disease.
1. Welsh AL, Ede M. Inositol hexanicotinate for improve nicotinic acid therapy. Int Record Med. 1961;174:9-15. 2. Sommer H. Nicotinic acid levels in the blood and fibrinolysis under the influence of the hexanicotinic ester of m-inositol. Arzneim Forsch. 1975;15:1337. 3. Dorner VG, Fischer FW. The influence of m-inositol hexanicotinate ester on the serum lipids and lipoproteins. Arzneim Forsch. 1961;11:110-113. 4. El-Eneim AMA, Hafez YS, Salem H, Abdel M. The role of nicotinic acid and inositol hexanicotinate as anticholesterolemic and antilipemic agents. Nutr Reports Int. 1983;28:899-911.