Niacin, or vitamin B3, remains a confusing issue for many people. It shouldn't be.
It doesn't help that most physicians and many pharmacists also do not understand the basic issues surrounding niacin. The only reason why there is any level of prevailing knowledge about niacin is that Kos Pharmaceuticals managed to "pharmaceuticalize" a niacin preparation, prescription Niaspan, that provided the revenue to fund professional "education."
Niacin can be helpful to increase HDL, reduce small LDL particles and shift them towards the more benign large particles, reduce triglycerides, and reduce lipoprotein(a).
So here's a brief description of the various forms that you will find niacin:
Immediate-release niacin--Also called crystalline niacin or just niacin. This is the original niacin that releases within minutes of ingestion. Because it releases rapidly, it triggers the most intense "hot flush." While this form of niacin works wonderfully well, is the safest, and is dirt cheap, the majority of people are simply unable to tolerate the intense flush. It also works best taken twice a day, generating two intolerable flushes per day.
Slow-release niacin--These preparations were popular in the 1980s, since the slow 12 to 24 hour pattern of release minimized the annoying hot flush. But, with prolonged use, it also became apparent that an unnaceptable frequency of liver toxicity developed. Unfortunately, this means that any niacin preparation that trickles niacin out over an extended period, including many of the slow-release preparations now sold in health food stores and pharmacies, have potential for liver toxicity. These preparations should be avoided.
6-hour release niacin--Releasing niacin more slowly than immediate-release niacin but more rapidly than slow-release niacin, 6-hour release (or what the Niaspan people call "extended-release" niacin) is nearly as effective as immediate-release niacin with approximately the same low potential for liver toxicity. It is far less liver toxic than slow-release niacin. 6-hour release niacin therefore offers the best balance between effectiveness and safety. Preparations that show this pattern of release include Niaspan ($180 per month), the poorly-named Sloniacin (about $8 per month), and Enduracin (about $7 per month) for 1000 mg per day. (Some Track Your Plaque Members have also determined that several other over-the-counter preparations have been demonstrated to share a similar pattern of release.)
Then there are the scam products that have no useful effect at all:
Flush-free or no-flush niacin--Inositol hexaniacinate, or 6 niacin molecules bound to the sugar, inositol, has no effect in humans, at least not with the dozen or so preparations that I've seen used. Nor are there any data to document the effectiveness of flush-free niacin. It's also more expensive.
Nicotinamide--This niacin derivative likewise has no effect on the usual targets for niacin treatment.
While I used to prescribe Niaspan, the ridiculous pricing and aggressive marketing really turned me off. I now advise my patients and our online followers to use only Sloniacin or Enduracin, unless you can tolerate immediate-release niacin.