Compound or practice · Supplement
Niacin (B3)
Corrects pellagra, powerfully shifts blood lipids — but as a heart drug it failed to cut events and added harm.
- Overall grade
- Grade B
- Last revised
- 4
- graded outcomes
- 0
- references listed
A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.
2 at grade A · 1 at grade B · 1 at grade D — 4 graded rows
What is known
Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.
- PellagraEvidence grade A
Definitional
Largehigh
- HDL / triglyceridesEvidence grade A
Strong lipid-panel effect
Largehigh
- Non-melanoma skin cancer (nicotinamide)Evidence grade B
In high-risk patients
Smallmixed
- Cardiovascular eventsEvidence grade D
AIM-HIGH, HPS2-THRIVE null + harm
Trivialhigh
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Thin evidence: Cardiovascular events (grade D).
- Studies disagree: Non-melanoma skin cancer (nicotinamide) (mixed agreement).
The evidence in words
What it is
Niacin is the B-vitamin precursor to NAD/NADP, the central redox coenzymes of metabolism. Pharmacologic doses of nicotinic acid were once a mainstay lipid drug; nicotinamide is the non-flushing amide form used for skin and NAD-precursor purposes.
How it works
As NAD/NADP it participates in hundreds of reactions. At gram doses nicotinic acid inhibits hepatic VLDL/triglyceride production and raises HDL — an impressive lipid-panel effect that, unusually, did not translate into fewer cardiovascular events.
What the evidence shows
Grade A for pellagra. As a cardiovascular therapy its story is a cautionary tale: it moves lipids dramatically but the AIM-HIGH and HPS2-THRIVE trials found no event reduction on top of statins and signals of harm (glucose disturbance, infection, bleeding). Nicotinamide has separate, modest evidence for reducing non-melanoma skin cancers in high-risk people.
How to use it
Requirement is milligrams from food. Pharmacologic niacin for lipids is largely abandoned and should only ever be used under a clinician. Nicotinamide 500 mg twice daily is the skin-cancer-prevention protocol in high-risk patients.
Safety & interactions
Nicotinic acid causes prostaglandin-mediated flushing and, at high doses, liver stress and glucose elevation. Do not self-prescribe gram doses.
Bottom line
You need milligrams to avoid deficiency and get them from food. The high-dose 'raise your HDL' era is over — it improved the panel without improving outcomes. Leave pharmacologic niacin to physicians.
How it is used
As the entry records it, from the studies it summarises. Not a recommendation for you — doses that suit a trial population may not suit you.
- Skin (nicotinamide)
- 500 mg twice daily in high-risk patients, under care.
Related reading
Entries that share this one's tags or conditions.
- Niacin (B3) for Cardiovascular eventsEvidence grade D — AIM-HIGH, HPS2-THRIVE null + harmEvidence grade D
- Niacin (B3) for HDL / triglyceridesEvidence grade A — Strong lipid-panel effectEvidence grade A
- Niacin (B3) for Non-melanoma skin cancer (nicotinamide)Evidence grade B — In high-risk patientsEvidence grade B
- Niacin (B3) for PellagraEvidence grade A — DefinitionalEvidence grade A
Sources
This entry lists no references of its own.
Last revised . A grade is this entry's reading of the evidence, not medical advice.