Nicotinic acid triggers release of prostaglandins, which relax smooth muscle in blood vessel walls
This causes immediate flushing — redness, warmth, tingling — especially in the face and chest
🩸 Effect: Increases blood flow temporarily, particularly to the skin and extremities
💡 Some people mistake this flush for an allergic reaction — it’s normal, though uncomfortable.
2. Improves Cholesterol Profile
This is where niacin has the strongest medical evidence:
✅ Raises HDL (“good”) cholesterol
Up to 15–35% increase
✅ Lowers LDL (“bad”) cholesterol
Modest reduction
✅ Reduces triglycerides
By 20–50% at high doses
🩺 For decades, doctors prescribed prescription-strength niacin to help manage cardiovascular risk — especially in patients who couldn’t tolerate statins.
⚠️ However, recent studies (like AIM-HIGH and HPS2-THRIVE) showed niacin didn’t significantly reduce heart attacks or strokes when added to modern treatments like statins.
As a result, its use has declined — but it’s still prescribed in specific cases.
3. May Help Peripheral Artery Disease (PAD)
In people with poor leg circulation due to PAD:
Niacin may improve blood flow by enhancing vasodilation
Some report reduced leg pain during walking (claudication)
🩺 Still considered experimental — not first-line treatment.
⚠️ Important Risks & Side Effects
Despite benefits, high-dose niacin is not safe for everyone.
❗ Liver Damage
People with liver disease; requires monitoring
❗ High Blood Sugar
Can worsen insulin resistance — risky for diabetics
❗ Gout Flares
Increases uric acid levels
❗ Stomach Irritation
Nausea, bloating, ulcers
❗ Severe Flushing
Can be intense; often improves over time
❗ Low Blood Pressure
Especially when combined with other meds
🚫 Never self-prescribe high-dose niacin — doses above 500 mg/day require medical supervision.
