While no one needs large doses of niacin, some take it as a supplement to reduce the risk of heart disease and atherosclerosis. Large daily doses of niacin may help to lower LDL cholesterol ("bad" cholesterol) and increase HDL cholesterol ("good" cholesterol). However, it can have uncomfortable side effects such as experiencing a niacin flush. Here is what you need to know about niacin.

What Is Niacin?

Niacin is also known as vitamin B3, found in many foods including chicken and turkey breast, beef liver, tuna, salmon, lentils, rice, peanuts, and potatoes, among others. Niacin helps convert food into energy.

Benefits of Niacin Supplements

Most people in the U.S. and other developed countries get enough niacin in their diet to meet their daily requirements. However, studies show that large doses of niacin may help dyslipidemias, an imbalance in the fat protein HDL and LDL cholesterol, triglycerides, and total cholesterol.

Symptoms of a Niacin Flush

A niacin flush is a common side effect of taking large doses of niacin (vitamin B3) supplements. The flush happens when niacin causes the small blood vessels in your skin to dilate so more blood can rush through. It isn't harmful but can scare you if you don't know it's coming. Almost everyone who takes large doses of niacin experiences this flush about 30 minutes after taking a large dose of 30mg to 50mg or more.

Niacin flush includes reddening of the skin accompanied by a burning or itching sensation. Flushing of the face is most common but can also occur in the neck and upper body. The flush improves over time and is usually gone within an hour or two.

The flush is generally harmless but may occasionally be accompanied by a headache, dizziness, or drop in blood pressure. If you experience these symptoms with a niacin flush, talk to your healthcare provider for advice.

Preventing a Niacin Flush

There are ways you can prevent a niacin flush while still reaping the benefits of niacin supplementation. Changing the dose or formulation, taking the supplement with food, and adding adjunct therapies help.

Change Your Niacin Dose

You won't get the niacin flush reaction after taking multiple vitamins that contain smaller amounts of niacin; it only happens when you take massive doses. The average adult needs about 14mg daily, so mega doses of individual niacin supplements are far more than anyone needs.

Change the Formulation

To avoid or lessen the niacin flush, you could use time-release forms of niacin, which are absorbed and metabolized slower than regular niacin.

Another alternative is inositol hexanicotinate, which your body converts to niacin. The conversion is slow enough to avoid flush in most people. There is evidence this does not have the same lipid-lowering benefits as niacin. One review of studies shows it can positively affect LDL, triglycerides, and total cholesterol in those with metabolic disorders. However, it did not affect HDL cholesterol levels.

Take Niacin With an NSAID

Taking a regular aspirin about 30 minutes before taking niacin supplements may also help reduce the discomfort, but probably won't eliminate it. Other NSAIDs can also help manage the symptoms of a niacin flush. The key is taking it with niacin so its benefits are in effect when the niacin flush starts.

Take Niacin With Food

Eating food when you take your niacin supplement can help slow niacin's absorption, easing the effects of the flush. If you take niacin in the morning, get into the habit of taking it right after you eat breakfast.

Treating a Niacin Flush

If you find yourself dealing with a niacin flush, there is unfortunately not much you can do to treat the symptoms of a single episode. A niacin flush will last up to two hours, although symptoms typically subside more quickly.

As mentioned, taking an NSAID like aspirin or ibuprofen can help ease some of the symptoms of a niacin flush. The physical discomfort, such as a prickling feeling, can be mitigated by these pain-controlling medications.

Niacin Requirements

Along with thiamin, riboflavin, and others, niacin is an essential B-complex vitamin your body needs to convert macronutrients from foods into energy for daily activities. It also helps your digestive system and supports normal skin and nerve function.

Most people don't need to take niacin because there's plenty of niacin in the foods found in a typical diet, even diets that aren't all that healthy. Nuts, legumes, eggs, poultry, beef, and seafood are all high in niacin, and it's found in smaller amounts in most other foods. So as long as you eat daily, you're getting plenty of niacin.

A Word From Verywell

Be careful if you're thinking about taking niacin for your high cholesterol levels. Even though the niacin flush is harmless, large doses can interact with different medications. Long-term niacin use can cause liver damage, skin rashes, gastrointestinal problems, and elevated blood sugar. Discuss niacin supplements with a healthcare provider before taking them.