Background: Nicotinic acid is an effective treatment for dyslipidemia, but the content of over-the-counter niacin is not federally regulated. As a result, patients may use preparations of over-the-counter niacin that do not contain free nicotinic acid.
Objective: To characterize the types, costs, and free nicotinic acid content of over-the-counter niacin preparations and to review literature on the use of over-the-counter niacin for dyslipidemia.
Data Sources: Commonly used over-the-counter niacin preparations (500-mg tablets or capsules) from the 3 categories of immediate-release, sustained-release, and no-flush were purchased at health food stores and pharmacies and from Internet-based vitamin companies. Pertinent literature on the use of over-the-counter niacin was obtained by searching PubMed.
Measurements: For each preparation studied, the monthly cost of therapy (at 2000 mg/d) and the free nicotinic acid content (quantified by high-performance liquid chromatography) were reported.
Data Synthesis: On average, immediate-release niacin preparations cost $7.10 per month, sustained-release preparations cost $9.75 per month, and no-flush preparations cost $21.70 per month. The average content of free nicotinic acid was 520.4 mg for immediate-release niacin, 502.6 mg for sustained-release niacin, and 0 for no-flush niacin.
Conclusions: No-flush preparations of over-the-counter niacin contain no free nicotinic acid and should not be used to treat dyslipidemia. Over-the-counter sustained-release niacin contains free nicotinic acid, but some brands are hepatotoxic. Immediate-release niacin contains free nicotinic acid and is the least expensive form of over-the-counter niacin.