: Online specialty stores like iHerb and Vitacost often provide high-potency options, such as 1000mg sustained-release tablets.
: Walmart and Amazon carry a broad selection of brands including Nutricost, Nature's Way, and 21st Century.
: Retailers like CVS and Walgreens stock standard 500mg tablets, often used for treating niacin deficiency or as a general supplement. Common Product Options Niacinamide 1000 mg Tablets - NOW Foods
