Dr. Axe > Nutrition > Vitamins & Minerals

Niacin Flush: Heart-Healthy Treatment or Hazardous Health Risk?

February 6, 2018

Niacin, also known as vitamin B3 and niacinamide, is a water-soluble vitamin that plays an important role in heart health. A niacin flush can be a temporary side effect of taking niacin (vitamin B3), or it can be the intentional act of taking higher doses of niacin for a particular health concern. What are some niacin uses? For starters, niacin has been used since the 1950s to lower elevated LDL (bad) cholesterol and triglyceride levels in the blood. (1)

So what is a niacin flush exactly? Let’s take a look at what it is, along with the possible benefits and serious risks of a niacin flush.

What Is a Niacin Flush?

What is niacin? Niacin or vitamin B3 is an essential vitamin we should all be getting in our diets on a daily basis. According to current USDA standards, adults and children over the age of four should consume about 16 milligrams of B3 per day. (2) What is niacin used for? At significantly higher doses it is used to treat hyperlipidemia — or high cholesterol — and lower the risk of cardiovascular health concerns. (3)

Vitamin B3 is one of eight B vitamins. This B3 vitamin is also commonly known as as niacin or nicotinic acid. There are also two other forms of the vitamin, niacinamide and inositol hexanicotinate, but these versions have different effects from niacin.

Niacin, or vitamin B3, can naturally be obtained in the diet. Foods high in niacin include things like grass-fed beef, free-range chicken, lamb, salmon, sardines, sunflower seeds and tahini. This B vitamin can also be obtained by supplementing with niacin pills. Like the other B vitamins, niacin is water-soluble rather than fat-soluble, which means that the body does not store it.

What does niacin do? Like the other B vitamin, niacin or B3 helps our bodies convert the food we eat into usable fuel. More specifically, niacin also helps the body to produce key sex hormones as well as stress-related hormones in the adrenal glands and other parts of the body. Niacin benefits also include the vitamin’s ability to decrease inflammation and boost blood circulation. (4)

So what is a niacin flush? Niacin side effects can include a niacin flush, which is when someone temporarily experiences red, warm and tingling burning and/or itchy skin after taking a niacin supplement. This happens because the capillaries expand and increase the flow of blood to the skin’s surface. A niacin flush is a common visible reaction to high doses of niacin or a niacin overdose. It can look and feel somewhat like a sunburn, but it typically begins 15 to 30 minutes after taking niacin and only lasts for about an hour. The flush is considered harmless, but it can be uncomfortable, which is a reason why companies now make flush-free niacin supplements. (5)

For specific health concerns, some people intentionally take higher doses of niacin, which is also referred to as a niacin flush because they are basically flushing their bodies with niacin. That’s the type of niacin flush I’m focusing on here. Is a niacin flush good for you? Research has shown that it can helpful for certain people.

Benefits

1. Helps Decrease LDL Cholesterol and Triglycerides

According to a study published in the American Journal of Medical Science, previous research has demonstrated that “in pharmacological doses, niacin (vitamin B3) was proven to reduce total cholesterol, triglyceride, very-low-density lipoprotein, and low-density lipoprotein levels, and to increase high-density lipoprotein (HDL) levels.”

The goal of this small 2013 study was to look at the impact of 12 weeks of niacin treatment on the lipid profile and oxidative stress status in patients with low levels of HDL cholesterol, specifically where good cholesterol was less 40 mg/DL. Both low HDL levels and oxidative stress are typically indicative of a higher risk for heart problems.

The study included 17 patients with hypercholesterolemia (high cholesterol) and low HDL cholesterol along with eight healthy control subjects. Overall, the study found that niacin supplementation decreased oxidative stress and triglyceride levels while significantly increasing HDL levels in the high cholesterol subjects. (6)

2. Can Increase Good Cholesterol

Research has shown that supplementing with high doses of niacin may be able to help increase HDL (“good”) cholesterol levels.

As a scientific article published in the International Journal of Clinical Practice points out, “Therapeutically used for more than 50 years, niacin is the most effective clinically available agent for increasing high-density lipoprotein cholesterol (HDL-C) levels.” Multiple studies have shown that for people with abnormally high overall cholesterol, niacin may increase HDL cholesterol by 20 percent to 40 percent. (7)

3. Aids in Reducing Hardening of the Arteries

Niacin is known to be used for the clinical therapy of atherosclerosis. Studies to date have pointed toward niacin’s ability to reduce hardening of the arteries, also known as atherosclerosis, for some people. As discussed in one scientific review, niacin has been shown to selectively increase the plasma levels of Lp-AI, a component of HDL that has a cardio-protective effect in patients with low HDL levels. (8) In addition, niacin supplementation has been shown to significantly decrease oxidative stress, which is known to contribute to atherosclerosis. (9, 10)

A study published in 2015 in the Medical Science Monitor revealed that in animal subjects, niacin was able to inhibit vascular inflammation and also inhibit apoptosis (programmed cell death) of of vascular smooth muscle cells. Overall, niacin appeared to inhibit the progress of atherosclerosis in animal subjects. (11)

4. Detoxes the Body

Common Internet searches for niacin include “niacin flush drug test” and “niacin flush thc.” What’s the story with that? Apparently, some people conduct a niacin flush in an attempt to pass a drug test.

If someone is looking to detox from drugs, can a niacin flush help? Some believe it can help rid the body of drug metabolites by upping the rate of fat breakdown in the body where the metabolites typically deposit themselves. However, taking a massive amount of niacin pills right before a drug test is just outright dangerous. If niacin is going to be taken to detox from drugs, it should be done gradually and with the guidance of a medical professional. (12)

5. Aids Weight Loss

It’s not hard to find niacin weight loss articles, but can niacin really help you lose weight? The idea just mentioned — that niacin can help to break down fat and get rid of toxins stored in fat cells — is why some say it can help with detox and weight loss. However, there are not many broad or well-done scientific studies to back up niacin flush for weight loss.

However, one study placed mice on a high-fat diet or a control diet, and after six weeks they were given either vehicle or niacin treatments for five weeks. The researchers concluded, “Niacin treatment attenuates obesity-induced adipose tissue inflammation through increased adiponectin and anti-inflammatory cytokine expression and reduced pro-inflammatory cytokine expression in a niacin receptor-dependent manner.” (13)

6. Helps Treat Pellagra

Pellagra is a rare health condition resulting from a deficiency in vitamin B3. Alcoholics as well as people with HIV/AIDS are risk for developing pellagra. Niacin is approved by the FDA as a pellagra treatment. (13)

How to Follow a Niacin Flush

If you’re wondering how long or how often to do a niacin flush as well proper dosage, always speak to your health care provider. Typically, doctors advise taking niacin with food and gradually increasing niacin dosage over the course of several weeks. Niacin extended-release supplements are often recommended. This version of niacin is designed to reduce the chance of skin flushing.

Here’s an example of recommended dosing for a niacin flush with an extended-release niacin supplement: (14)

Weeks 1–4: Daily dose of 500 milligrams of niacin extended-release taken at bedtime
Weeks 5–8: Daily dose of 1,000 milligrams of niacin extended-release taken at bedtime (can be one 1,000-milligram tablet or two 500-milligram tablets)

After eight weeks, a doctor will typically evaluate the patient’s response to the niacin. Female patients have been known to require lower doses than male patients to see a desirable response. If the response to 1,000 milligrams is not adequate, the dosage may be increased to 1,500 milligrams and then 2,000 milligrams each day if needed. Niacin doses over 2,000 milligrams daily are usually not recommended. It’s also recommended not to raise niacin dosage more than 500 milligrams over the course of four weeks.

Niacin Flush Recipes

If you’re looking to up your niacin intake through your diet, incorporate niacin foods into your meals regularly.

There are also a lot of delicious recipes that are notably high in vitamin B3, including:

A niacin flush (the visible symptom) typically occurs from supplemental doses of niacin at 50 milligrams or higher. When niacin is consumed in foods, it is not likely to experience the visible niacin side effect known as a niacin flush.

Potential Niacin Side Effects and Caution

Taking niacin can cause skin flushing, particularly when you first start taking it. Minor side effects of niacin supplementation can also include upset stomach and diarrhea. These mild side effects usually decrease over time. (15)

Is a niacin flush dangerous? High doses of niacin have been associated with liver damage, gastrointestinal problems, glucose intolerance, low blood pressure, heart rhythm changes and other health issues. This is why it’s important to speak with your health care provider about the appropriate niacin supplement and dose for your particular needs.

What about no-flush niacin or niacin flush-free? No-flush niacin often contains inositol nicotinate, also known as inositol hexanicotinate. These forms of niacin are different than niacin (nicotinic acid) and may not provide the same effects as niacin and hence not produce the same visible flushing effect. Some common recommendations for reducing skin flushing from niacin supplementation include avoiding alcohol and spicy food. Also, taking niacin with food and starting with a lower dose and gradually increasing the dosage over time are known to reduce the chances of skin flushing. (16)

A niacin flush as well as niacin supplementation is often not recommended for anyone with the following conditions: (17)

Active kidney disease
Active liver disease
Active stomach ulcer
Alcoholism
Blood clotting disorders, such as hemophilia
Glaucoma
Gout
Low blood pressure
Oversensitivity to niacin
Type 2 diabetes with uncontrolled blood sugar levels (since niacin can increase blood sugar levels)

Is it typically not recommended to take niacin extended-release tablets if you are pregnant, trying to become pregnant or breastfeeding.

Stop taking niacin or niacinamide at least two weeks before surgery. It’s possible for niacin to make allergies worse by increasing histamine levels in the body.

If you have any of these health concerns, especially diabetes or gallbladder disease, speak with your doctor before taking niacin. In general, always speak to your doctor before conducting a niacin flush. Some doctors recommend combining statins with niacin, which can increase the risk of side effects.

Final Thoughts

A niacin flush can be a temporary side effect of taking niacin; it’s also a protocol used by some physicians to lower lipid profiles and boost heart health.
Studies have shown that niacin flush benefits can include reduced LDL cholesterol, triglyceride levels and oxidative stress while increasing HDL cholesterol.
Niacin flush should only be conducted under a doctor’s supervision.
There are major risks to a niacin flush that should be seriously considered before choosing it as a line of treatment.
It’s not hard to obtain niacin in your diet on a daily basis through healthy niacin-rich foods like grass-fed beef, turkey, avocados and peas.
Taking B vitamins together in the form of a high-quality B vitamin complex supplement allows the vitamins to work better in the body since the B vitamins interact with one another to make absorption and conversion possible.
Do not attempt to conduct a niacin flush without the direction of your doctor.