How does niacin lower blood cholesterol levels?


Niacin has diverse actions affecting cholesterol formation. A primary effect appears to be that it decreases the production of triglycerides in the body, which might be the mechanism that allows this drug to decrease low-density lipoprotein (LDL) or "bad" cholesterol levels. Nicotinic acid also raises high-density lipoprotein (HDL) or "good" cholesterol levels via mechanisms not yet understood.

Some of the most common side effects of niacin drugs are flushing, hot flashes, itching and headache. People who take niacin for a prolonged period of time, especially at high doses, should have periodic liver function tests.

Dr. Ozgen Dogan
Cardiologist (Heart Specialist)

Niacin, a type of vitamin B, can be very useful if you need to increase your good cholesterol (high-density lipoprotein [HDL]). It has been shown to increase HDL by 10 to 30 percent. Your doctor will prescribe a dose that is much higher than the amount found in multivitamins. Side effects can include temporary flushing of the skin (which can be counteracted by aspirin) and/or upset stomach.

Dr. Darria Gillespie, MD
Emergency Medicine Specialist

Niacin (vitamin B3) limits the production of LDL cholesterol in the liver. It can lower LDL, increase HDL, and lower triglycerides. Niacin is available as a single drug (Niacor, Niaspan) or combined with a statin (Advicor, Simcor).

Current US cholesterol management guidelines state that non-statin drugs, including niacin, are not first-line therapy, but can be added to statins for the following people: those age 75 or younger who have had a heart attack or stroke; those age 40 to 75 with diabetes; and those with untreated LDL 190 mg/dL or above.

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Dr. Joseph Saseen, PharmD
Cholesterol Management Specialist

Niacins lower LDL cholesterol, but overall, statins are the best cholesterol-lowering agents as they are proven to reduce the risk of heart disease and cardiovascular events.

Niacin/nicotinic acid (Advicor, Niacor, Niaspan) is a type of cholesterol-lowering medication. It is especially effective in combination with bile acid binders. Side effects include flushing (especially with crystalline preparations), rash, headache, nausea, vomiting, diarrhea, flatulence, indigestion, low blood pressure, elevated uric acid blood levels, high blood sugar, peptic ulcer activation, cardiac arrhythmias, dry skin and abnormal liver enzymes (especially with sustained-release preparations). Do not take niacin if you have chronic liver disease, active peptic ulcer or arterial bleeding. Use with great caution if you have gallbladder disease, diabetes, severe gout or high blood levels of uric acid. Tests of blood glucose, uric acid, and liver functions need to be performed regularly.

Niacin or nicotinic acid, the water-soluble B vitamin, improves all lipoproteins when given in doses well above the vitamin requirement. Nicotinic acid lowers total cholesterol, LDL-cholesterol and triglyceride levels, while raising HDL-cholesterol levels. There are three types of nicotinic acid: immediate release, timed release, and extended release. Most experts recommend starting with the immediate-release form; discuss with your doctor which type is best for you. Nicotinic acid is inexpensive and widely accessible to patients without a prescription but must not be used for cholesterol lowering without the monitoring of a physician because of the potential side effects.

All patients taking nicotinic acid to lower serum cholesterol should be closely monitored by their doctor to avoid complications from this medication. Self-medication with nicotinic acid should definitely be avoided because of the possibility of missing a serious side effect if not under a doctor's care.

Nicotinic acid reduces LDL-cholesterol levels by 10 to 20 percent, reduces triglycerides by 20 to 50 percent and raises HDL-cholesterol by 15 to 35 percent.

A common and troublesome side effect of nicotinic acid is flushing or hot flashes, which are the result of blood vessels opening wide. Most patients develop a tolerance to flushing and, in some patients; it can be decreased by taking the drug during or after meals or by the use of aspirin or other similar medications prescribed by your doctor. The extended release form may cause less flushing than the other forms. The effect of high blood pressure medicines may also be increased while you are on niacin. If you are taking high blood pressure medication, it is important to set up a blood pressure monitoring system while you are getting used to your new niacin regimen. A variety of gastrointestinal symptoms including nausea, indigestion, gas, vomiting, diarrhea, and the activation of peptic ulcers have been seen with the use of nicotinic acid.

This answer is based on source information from the National Heart, Lung and Blood Institute.

This compound is more commonly known as nicotinic acid, a water-soluble B vitamin. It decreases triglycerides by limiting the liver's ability to produce low-density lipoprotein (LDL) cholesterol. Niacin appears to have stronger effects on high-density lipoprotein cholesterol and triglycerides than it does on LDL cholesterol. It comes in capsule and tablet forms, both regular and time released. An initial dose will probably be low, then gradually increased to between 1.5 grams and 6 grams a day.

Unfortunately, you can't lower your cholesterol by taking a vitamin supplement -- to have such an effect it must be taken in doses well above the daily vitamin requirement. Although nicotinic acid is inexpensive and available over the counter, never take it for cholesterol reduction without a healthcare professional's oversight because of potential side effects.

Niacin also widens blood vessels, making flushing and hot flashes frequent side effects. These side effects may be reduced by taking the drug with meals or by taking aspirin or a similar medication with nicotinic acid. The extended release form, available by prescription as Niaspan, results in less flushing and liver toxicity than the immediate or sustained release forms.

Nicotinic acid can also intensify the effect of high blood pressure medication and produce various gastrointestinal problems—nausea, indigestion, gas, vomiting, diarrhea and activation of peptic ulcers. Serious side effects include liver problems, gout and high blood sugar, with risk rising in tandem with the dose.

This drug may not be prescribed if you have diabetes because it can raise blood sugar slightly. If you have diabetes, talk about the pros and cons with your healthcare professional.

Continue Learning about Vitamin B3 Niacin

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.