Niacin Flush: Why Does It Happen?

One of the B vitamins that aid in transforming food into energy is called niacin.

Niacin Flush

Niacin is one of the vital B vitamins that the body needs. It is commonly known as vitamin B3 which transforms the food you eat into energy. While it is not a common supplement, some people take this as a treatment for high cholesterol. However, a high dose of this B vitamin causes niacin flush, but what is it and what causes it? Plus, here’s what you need to know to prevent it.


What Is Niacin Flush?

As mentioned, niacin is one of the B complex vitamins that are important in transforming consumed food into energy for the body. However, overconsumption of niacin leads to a flush which is characterized by reddening of the skin. A burning or itching sensation may accompany the flush as well.  This side effect is not harmful but can be alarming, especially if you don’t realize that it may happen.

Vitamin B3 is usually prescribed as a supplement in the treatment of high cholesterol. The supplement commonly used is nicotinic acid, which can be categorized into two forms. One is immediate release, while the other is extended-release.

Extended-release nicotinic acid supplements dissolve slowly due to its special coating. On the other hand, the immediate release is absorbed by the body all at once. Since it is “immediate” release, the flushing becomes a common side effect. It is because of high levels of nicotinic acid that causes the capillaries in the body to expand. This, in turn, increases the flow of the blood to the skin’s surface. Thus, this creates a red, flushed appearance.

Another form of niacin that’s prescribed as a supplement is niacinamide. However, this supplement is ineffective in altering cholesterol levels in the blood. It also does not cause flushing. Other medicines that can trigger a flush include hormone replacement therapies and antidepressants.


Symptoms of a Flush

This side effect takes approximately 10 to 20 minutes to manifest, especially if a large dose that is around 250 milligrams or more is taken. It affects the upper body and the face and is manifested as:

  •         Blushing: which may appear as a mild blush or as red as sunburnt skin
  •         Burning, itching, or tingling sensation: which can be painful or uncomfortable
  •         Warm or hot sensation: felt on the skin

A flush disappears within one to two hours. For people who are used to high doses of niacin, they have already developed a tolerance for it, and a flush rarely happens.


Benefits of Niacin

Vitamin B3 is prescribed as a supplement to treat high cholesterol. Moreover, some doctors also prescribe this as a supplement to prevent diseases of the heart. Consuming high doses of this B vitamin has excellent effects on the body. Some of these include the following.

  1. Increases Good Cholesterol

Good cholesterol, also known as HDL, is increased with the help of niacin. This vitamin prevents apolipoprotein A1 breakdown, which is essential in creating HDL. Studies have proven that niacin boosts HDL by approximately 20 to 40 percent.

  1. Reduces Bad Cholesterol

While it boosts HDL, this B vitamin also reduces the bad cholesterol known as LDL. It speeds up the breakdown of the apolipoprotein B. According to studies, vitamin B3 can lessen the amount of LDL cholesterol by about 5 to 20 percent.

  1. Lowers Triglycerides

Aside from lowering the levels of LDL, it also aids in lowering the level of triglycerides in the blood. It does this by interfering with an essential enzyme for the production of triglycerides. Studies have shown that niacin not only decreases the levels of triglycerides but lowers oxidative stress as well.

  1. Reduces Atherosclerosis

Atherosclerosis is a condition where the arteries are hardened due to the buildup of cholesterol. Recent studies claim that niacin aids in reducing atherosclerosis by lowering oxidative stress.

  1. Helps in Weight Loss

Studies done on animals prove that this B vitamin can help in reducing fat. Additional exploration needs to be done to strengthen this claim. Nonetheless, this has not stopped other individuals from taking niacin as a supplement to aid in their weight loss. Moreover, it is said to help detoxify the body.

  1. Treats Pellagra

This is a rare condition that is due to a deficiency in niacin. Individuals with AIDS and alcoholics are at risk for this condition. Vitamin B3 has been approved by the Food and Drug Administration as a treatment for pellagra.

Take note that niacin is not the first line of defense when it comes to battling cholesterol problems. Nonetheless, it is the most favored prescription for individuals who do not respond effectively with statins. Statins are known as the preferred treatment for high cholesterol.

Niacin supplements, as well as other supplements, should be taken under the supervision of your attending physician. Always consult with your primary caregiver before taking medications. While the recommended daily intake (RDI) of niacin is 14 to 16 milligrams in a day, the dose prescribed for the treatment of high cholesterol is 1000 to 2000 milligrams daily.


Is It Dangerous?

While it may be painful or uncomfortable for some, it is generally harmless. However, a high dose of vitamin B3 may trigger other severe side effects, though rare. The most severe side effect is damage to the liver.

It may also cause stomach cramps. So, if you have an ulcer or are actively bleeding, then do not take niacin. If you are pregnant, then it is highly advised that you take the RDI of niacin. A high dose of this B vitamin is considered category C in drugs, which means it can lead to birth defects.



Massive amounts of vitamin B3 cause a flush. Lessen or avoid this side effect with the following strategies.

  • Opt for a Different Formula

As mentioned, immediate-release niacin supplements cause flushing. So, opt for the extended-release version. It is not only absorbed slower than the immediate release, but it is also metabolized at a slow rate.

  • Consume an Apple or Take Aspirin

Aspirin reduces the risk of getting the flush. Take around 325 milligrams 30 minutes before consuming your niacin supplements. This reduces the flushing, but it is unlikely to prevent it. Pectin in apples is said to have the same effect as with aspirin.

  • Eat a Snack

A low-fat snack taken before the supplement should lessen niacin flush. It is also advised that you eat a full meal prior to taking vitamin B3.

Niacin Flush

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