Niacin is a B vitamin that may help to effectively lower cholesterol, but the time it takes to do so may vary. Typically, it may take a few weeks for niacin to alter cholesterol levels.

Niacin, also known as vitamin B3, plays a role in converting the food a person eats into energy, through using fats and proteins.

It may help to increase high-density lipoprotein (HDL), or good cholesterol levels, while lowering low-density lipoprotein (LDL), or bad cholesterol, and triglyceride levels. As such, it may be useful for managing cholesterol levels.

Some forms of niacin may cause side effects such as flushing. Therefore, it is advisable to consult a physician before taking any niacin supplements.

In this article, we will discuss niacin and how quickly it may help to lower cholesterol levels. Additionally, we will explore how niacin works and other ways to manage cholesterol.

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How quickly niacin may lower cholesterol may depend on several factors. These include the current health of the person taking it, whether they are taking any prescribed medication such as statins, and the dosage of niacin.

Researchers have studied niacin either alone or in combination with statin therapy. One small 2020 study found that extended-release niacin therapy without any other cholesterol medication lowered total and LDL cholesterol and increased HDL over 16 weeks.

More extensive research into the cholesterol-reducing abilities of niacin has found efficacy over a number of years. However, results have varied, and some individuals had adverse effects.

Therefore, the American College of Cardiology and the American Heart Association advises that non-statin therapies such as niacin are not preferable to statins for reducing cardiovascular risk.

Niacin, or vitamin B3, is the generic name for nicotinic acid, nicotinamide, and niacinamide. Niacin is naturally present in many foods, and the body converts it to nicotinamide adenine dinucleotide (NAD), which it uses for energy and many other functions.

Evidence indicates that niacin lowers lipids (fats) in the blood and improves the cholesterol profile. Research indicates that niacin may stop the body from breaking down fats and help degrade harmful lipids such as very low-density lipoprotein (VLDL) and LDL.

While evidence notes that niacin can help to improve all lipoprotein levels, it can also cause side effects and may not reduce the risk of heart attack or stroke. As such, some doctors may not recommend niacin as an alternative to other cholesterol-lowering drugs.

Niacin is available as a supplement that people can buy in various formulations. Manufacturers may include niacin in supplements to lower cholesterol or as part of a multivitamin or B-complex. Doctors can also prescribe niacin as medication, for example, Niaspan.

Niacin comes in extended-release and immediate-release forms ranging in strength from 50–3000 milligrams (mg). Niacin is also available in a “flush-free” form as inositol hexanicotinate, which the body absorbs around 30% lower than nicotinic acid or nicotinamide

The niacin dosage that a doctor may recommend for high cholesterol is as follows:

  • 1500–3000 mg a day orally, divided into two or three dosages
  • a starting dose of 250 mg at bedtime, gradually increasing by 250 mg a day every 4–7 days up to 2000 mg a day
  • after 2 months, someone may increase the dose to 250–500 mg a day every 2–4 weeks up to a maximum of 6000 mg a day

People should take niacin without food. Additionally, some health experts may advise that 325 mg of aspirin 30 minutes before a dose can help reduce flushing.

Food sources of niacin

People can also consume niacin in food. For example, animal products such as beef, poultry, and fish provide about 5–10 mg of niacin per serving.

Additionally, plant-based foods such as nuts, leagues, and grains provide about 2–5 mg of niacin or nicotinic acid per serving. The recommended dietary allowance (RDA) for niacin is 16 mg niacin equivalent (NE) for males and 14 mg NE for females.

Experts list NE because the body can convert the amino acid tryptophan to niacin. Tryptophan-containing foods include meat, fish, and dairy products. However, people should note that food sources of niacin may not be adequate to lower cholesterol on their own.

Potential adverse effects and contraindications

Niacin may cause some adverse effects. Health experts note that taking dietary supplements containing 30 mg or more of nicotinic acid may cause itching, tingling, or burning on the skin. Niacin may cause the face, arms, and chest to turn red in what doctors call a “niacin flush.”

Other adverse effects may include:

  • elevated uric acid in the blood
  • gastrointestinal disorders
  • a rash
  • increased homocysteine levels
  • low blood pressure
  • indigestion
  • nausea
  • vomiting
  • paresthesia

Severe adverse reactions may include anaphylaxis, irregular heart rhythms, and liver toxicity.

Additionally, it is not advisable for some people to take niacin. This includes:

  • people with peptic ulcers
  • those who are pregnant or chestfeeding
  • individuals with diabetes or metabolic syndrome
  • people with liver disease or arterial bleeding

Anyone wishing to try niacin to lower their cholesterol should first seek advice from a health professional.

There are several other natural products and supplements that may help someone lower their cholesterol. According to the National Center for Complementary and Integrative Medicine, the following may be effective and safe:

People can consume these natural products as foods or supplements. However, they must consult a healthcare practitioner if they have a health condition or are taking medication.

To manage cholesterol, the Centers for Disease Control and Development (CDC) advises a person to keep within the following parameters:

  • total cholesterol of 150 mg per deciliter (mg/dL) is optimal
  • fasting triglyceride level less than 150 mg/dL
  • LDL-C level less than 100 mg/dL
  • HDL level greater than or equal to 40 mg/dL in males and 50 mg/dL in females

The National Heart, Lung, and Blood Institute (NHLBI) has the following tips for managing cholesterol:

  • choosing heart-healthy foods such as whole grains, fruits, and vegetables, and limiting saturated fats in meat, dairy products, and desserts
  • getting regular exercise and physical activity
  • maintaining a healthy weight
  • managing stress
  • quitting smoking
  • getting adequate good quality sleep
  • limiting alcohol

People can discuss how to improve their cholesterol profile with their doctor.

Niacin may help lower a person’s cholesterol levels. However, the time it takes to do this may vary according to their health, age, other medications, lifestyle behaviors, and dose of niacin.

Scientists have found niacin effective at lowering cholesterol in some studies, some of which they have conducted over many years.

While some research notes that niacin may be effective at lowering cholesterol, it can cause adverse effects and may not be preferable to statins. Therefore, it is advisable for a person to discuss managing their cholesterol with their healthcare professional.