Some niacin products are currently available in generic form. Niacin immediate-release tablets, which are available by prescription, come in generic form. However, the prescription extended-release tablets and over-the-counter dietary supplements do not come in generic form. Since dietary supplements are not evaluated by the FDA, there is no way of knowing whether they are truly "generic niacin" products.
Niacin (brand names include Niacor®, Niaspan®, Slo-Niacin®, and several others) is available both as a prescription medication and as non-prescription dietary supplements. Some, but not all, niacin products are available in generic form.
Of the prescription niacin products, Niacor (immediate-release tablets) is available as a generic but Niaspan (extended-release tablets) is not (see Generic Niaspan).
For non-prescription dietary supplement forms (including Slo-Niacin and many others), there are no generics. Dietary supplements are not evaluated by the United States Food and Drug Administration (FDA), the regulatory agency that determines which products are generically equivalent to each other. There may be store-brand, "generic" non-prescription niacin products, but it is impossible to know if they are equivalent to any of the brand-name products.
It is important to understand that different types of niacin are not interchangeable. They may vary significantly in both safety and effectiveness. Be sure to use only the type of niacin that your healthcare provider recommends.