Nicotinamide

Research summary

Human research on nicotinamide in healthy subjects primarily centers on its safety profile and dermatologic applications, particularly for acne and rosacea, where oral and topical formulations have demonstrated usefulness with generally good tolerability. At usual supplement and dermatologic doses, nicotinamide is largely well tolerated, with gastrointestinal discomfort, headache, fatigue, or dizziness reported mainly at higher doses or in specific patient populations. Data in healthy humans regarding systemic longevity or metabolic benefits are limited, and much of the enthusiasm for nicotinamide as an NAD+ precursor comes from mechanistic and animal work rather than robust clinical trials in healthy people. High-dose use has been associated with liver toxicity and muscle-related adverse effects in some contexts, especially when combined with statins or in individuals with kidney disease, highlighting that safety at pharmacologic doses is less well established than at nutritional levels. Overall, there is reasonable evidence for dermatologic benefits and deficiency prevention, while evidence for broader anti-aging or performance effects in healthy adults remains preliminary.