{"entity":{"id":"nicotinamide","kind":"drug","name":"Nicotinamide","aka":["Niacinamide","Vitamin B3 (amide)"],"tldr":"Nicotinamide is a cheap over-the-counter form of vitamin B3. Taken twice a day it cuts the number of new skin cancers in people who have already had several, by helping skin cells repair sun damage.","summary":"Nicotinamide (niacinamide) is the amide form of vitamin B3, available without prescription. Unlike niacin it does not cause flushing. In the Australian ONTRAC trial (New England Journal of Medicine, 2015), 386 people who had had at least two non-melanoma skin cancers in the previous five years took 500 mg twice daily or placebo for a year; new basal and squamous cell carcinomas fell by about a quarter, and actinic keratoses also fell. The benefit disappears when it is stopped.\n\nIt is now recommended in guidelines as chemoprevention for high-risk patients, including organ-transplant recipients, alongside sun protection and regular skin checks. Its proposed mechanism is replenishing cellular NAD+ so that ultraviolet-damaged DNA is repaired and the local immune suppression caused by sunlight is reduced.","status":"established","asOf":"2026-09-17","wikipedia":"https://en.wikipedia.org/wiki/Nicotinamide","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Nicotinamide"}],"tags":["subtype-drugs-wave"],"related":["acitretin"],"cancers":["basal-cell-carcinoma","cutaneous-scc"],"sections":[],"technologies":["chemoprevention"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"modality":"Oral vitamin B3 (over the counter; cytoprotective NAD+ precursor)","mechanism":"A precursor of NAD+ that supplies energy for DNA repair after ultraviolet damage and blunts the immunosuppression sunlight causes in skin.","approvals":[],"mechanismSteps":[],"toxicity":[],"access":[],"regulatoryEvents":[]},"route":"/drugs/nicotinamide/","neighbours":{"drug":[{"id":"acitretin","kind":"drug","name":"Acitretin","route":"/drugs/acitretin/"}],"cancer":[{"id":"basal-cell-carcinoma","kind":"cancer","name":"Basal cell carcinoma","route":"/cancers/basal-cell-carcinoma/"},{"id":"cutaneous-scc","kind":"cancer","name":"Cutaneous squamous cell carcinoma","route":"/cancers/cutaneous-scc/"}],"technology":[{"id":"chemoprevention","kind":"technology","name":"Chemoprevention & risk-reducing surgery","route":"/technologies/chemoprevention/"}]}}