Niacin (B3)
The flush vitamin. Niacin (vitamin B3) is essential for making NAD+, the coenzyme needed for hundreds of metabolic reactions. Famous for the "niacin flush" and its dramatic effects on cholesterol, niacin has a fascinating history from curing pellagra to modern longevity research.
Forms of Vitamin B3
Niacin (Nicotinic Acid)
Original form. Causes flush. Used for cholesterol. Converts to NAD+.
Niacinamide
No flush. Same NAD+ benefits. Used in skincare. Doesn't affect cholesterol.
NR (Nicotinamide Riboside)
Premium NAD+ precursor. No flush. Popular for longevity. More expensive.
NMN (Nicotinamide Mononucleotide)
One step closer to NAD+. Research darling. Longevity interest. No flush.
Inositol Hexanicotinate
"No-flush niacin." Releases slowly. Less effective for cholesterol than regular niacin.
Tryptophan
Body can make niacin from tryptophan. 60mg tryptophan = 1mg niacin. Inefficient.
What Niacin Does
NAD+ Production
- All forms ultimately become NAD+
- NAD+ needed for 500+ enzymatic reactions
- Energy production (ATP synthesis)
- DNA repair (PARP enzymes)
- Sirtuin activation (longevity genes)
High-Dose Effects
- Raises HDL significantly (20-35%)
- Lowers LDL and triglycerides
- Only nutrient to affect Lp(a)
- Shifts LDL to larger, less atherogenic particles
- Requires 1-3g daily (prescription range)
The Niacin Flush
What It Is
Warmth, redness, tingling—especially face, neck, arms. Feels like sunburn. Harmless but intense.
What Causes It
Prostaglandin release (PGD2). Vasodilation. Histamine release. Blood vessels expand.
How to Minimize
Start low (100mg), increase slowly. Take with food. Aspirin 30 min before. Apple or apple pectin.
Tolerance Builds
Flush decreases over 1-2 weeks of consistent use. Missing doses resets tolerance.
High-Dose Cautions
Liver
Extended-release forms more liver toxic. Monitor liver enzymes. Avoid with liver disease.
Blood Sugar
High doses can raise glucose. Diabetics need monitoring. May worsen insulin resistance.
Methylation
Metabolizing niacin uses methyl groups (SAM-e). Can deplete methylation if high-dose long-term.