Amount of Evidence: High Potential Benefits: Reasonable Safety: Very High
TABLE OF CONTENTS
What is niacinamide?
Niacinamide, also known as nicotinamide, is a form of vitamin B3. This essential vitamin supports healthy NAD+ levels, energy production, protection against oxidative stress, reparation of damaged DNA, and much more. While niacinamide is safer than nicotinic acid (another form of vitamin B3), it does not have the same cholesterol-lowering effects and it doesn’t increase NAD+ levels as much. For this reason, niacinamide is not as effective for increasing health span as many of the other forms. In this article, we will look at niacinamide’s main benefits, potential side effects, and how to use it the right way.
Potential benefits
It is important to note that all of the potential benefits mentioned below are dose-dependent. In general, the higher the dose you take, the more pronounced the effects will be. However, they do reach a plateau at a certain point. We will discuss the best dosing protocol later in this article.
Major benefits
Correcting a niacin deficiency – Severe vitamin B3 deficiency is called pellagra. The main symptoms of pellagra are “the three Ds”: dementia, diarrhea, and dermatitis (in severe cases, a fourth D can be added, death). Although it is unlikely that you will ever experience such a deficiency, an inadequate supply of dietary niacin can still lead to many health problems. The most common signs of niacin deficiency include fatigue, exercise intolerance, depression, and accelerated skin aging. People with a niacin deficiency also have a higher risk of developing esophageal cancer, skin cancer, and leukemia. The reason for this could be an impaired ability of the body to repair DNA.
Increased NAD+ levels – Unfortunately, niacinamide does not increase NAD+ levels as much as the other forms of vitamin B3 (nicotinic acid, NR, and NMN). In order for niacinamide to increase NAD+ and sirtuin activity, it must first be converted to NMN. This conversion requires an enzyme called NAMPT. NAMPT peaks in the morning and early afternoon and can also be increased by exercise, caloric restriction, and resveratrol. Even then, only 50-100 mg can be converted successfully.
Minor benefits
Reduction in acne – This effect is most notable in people who use niacinamide topically. Oral use is also likely to reduce the severity of acne.
Reduced wrinkles – Both topical use of niacinamide and oral use of vitamin B3 (at least in the form of nicotinic acid) have been shown to reduce wrinkles. Oral supplements are especially helpful for wrinkles caused by long-term sun exposure. With topical niacinamide, this effect is most notable for wrinkles around the eyes.
Skin quality – Topical nicotinamide makes the skin more elastic and reduces the reddening of the skin. In people with hyperpigmented spots, topical nicotinamide reduces skin pigmentation. Also, when topical niacinamide is applied to burned skin, the skin heals faster.
Decreased risk of CAD – One meta-analysis found that vitamin B3 supplements reduce the risk of CAD (coronary artery disease).
Production of ketones – When taken in a fasted state, even low doses of niacin can increase the production of ketone bodies.
Brain protection – In one study, nicotinamide riboside was able to prevent age-related brain damage and improve memory function in mice. This effect could apply to other forms of vitamin B3 as well since it is likely connected with increased NAD+ levels.
Reduced heart and liver fat – While vitamin B3 does not appear to reduce overall body fat, nicotinic acid has been shown to help burn fat around the liver and the heart. This effect may apply to niacinamide as well.
Unproven benefits
The effect of niacinamide supplements on these parameters is either not sufficiently researched or the science shows little to no efficacy in these areas.
Increased HDL cholesterol – While niacin is undoubtedly the most effective supplement for increasing HDL cholesterol, it is important to note that this effect only applies to nicotinic acid and extended-release niacin.
Decreased LDL cholesterol – Again, this effect applies only applies to the two forms mentioned above.
Lower triglycerides – Unlike nicotinic acid, niacinamide has not been proven to lower triglycerides.
Lower risk of death from cardiovascular diseases – Niacin supplements do not appear to significantly reduce mortality associated with cardiovascular diseases.
Apolipoprotein A – One study on nicotinic acid suggests an increase in ApoA, which would be cardioprotective. However, other studies show little or no effect on ApoA levels.
Apolipoprotein B – The reduction in ApoB has been noted in scientific studies but it is insignificant and has little to no impact on your health.
Blood flow – Most studies show that niacin does not increase blood flow. There may be a slight improvement in people who take niacin regularly over a long period of time and have low HDL-C levels.
Blood pressure – Niacinamide does not appear to affect blood pressure in healthy individuals. In hypertensives, nicotinic acid appears to be able to lower blood pressure in the short term. The same may apply to niacinamide.
Body fat – No study has shown any benefit of niacinamide for overall fat loss. However, nicotinic acid does lead to a reduction of fat around the liver and the heart and the same might apply to niacinamide.
Reduction in CRP (C-reactive protein) – Niacinamide supplements do not appear to lower CRP in healthy individuals or in dyslipidemics.
Inflammation – Vitamin B3 has no noticeable effect on inflammation.
Prevention of muscle atrophy – Muscle NAD+ levels have been shown to protect muscle mass as we age. As of 2022, only nicotinic acid has been proven to increase muscle NAD+.
Possible side effects
These side effects may only occur if you take high doses of vitamin B3 and often do not apply to all forms.
Weakness and lack of energy – This is another possible short-term effect that some people experience. Fortunately, it is not as common as niacin flushing when taking nicotinic acid. Some people actually feel energized after taking vitamin B3.
Decreased insulin sensitivity and diabetes – Long-term supplementation of high doses of nicotinic acid has been associated with worsened insulin sensitivity. Fasting insulin concentrations also tend to be higher in individuals who take niacin than in those who do not. Fortunately, this does not seem to be the case with niacinamide though.
Increased blood glucose – There appears to be a slight increase in fasting blood glucose levels in individuals taking high doses. Fortunately, this effect is small and may not occur in healthy individuals.
Liver damage – Very high doses of certain forms of B3 supplements may cause liver failure. In particular, nicotinic acid is the main form to be concerned about. Niacinamide does not appear to damage the liver nearly as much and the side effect can be mitigated to a large extent. However, it may still be a concern if your liver is already damaged.
Sirtuin inhibition – While niacinamide only inhibits sirtuin activity for a few hours after you take it, it is enough of a reason to consider other forms instead. However, there is also a way to get around this effect by boosting an enzyme called NAMPT. This can be done by caloric restriction, taking resveratrol, and taking niacinamide at the right time.
Worsened allergies – Vitamin B3 can lead to the release of histamine, which can increase the intensity of allergies in the short term.
Who should avoid taking niacinamide?
You should probably avoid high doses of vitamin B3 if you:
suffer from liver disease
are looking for the cholesterol-lowering or NAD+ boosting effects of niacin (since other forms are more effective in these areas)
Who will benefit the most?
You should definitely consider taking niacinamide supplements if you:
are experiencing symptoms of vitamin B3 deficiency
suffer from a digestive disorder (such as Crohn’s and megaduodenum)
are under a lot of physical and mental stress
Forms of vitamin B3
There are 7 main forms of vitamin B3 supplements. Each has its distinct advantages and disadvantages.
Niacinamide – The form you are reading about right now.
Nicotinic acid – This form, often simply called niacin, is often used in high doses to alter cholesterol levels. It is also the form that causes niacin flush because we absorb this form rapidly. The disadvantage of nicotinic acid is that it may increase your risk of diabetes. The main reason to take this form instead of the other ones is that it is more effective in most areas (particularly, increasing NAD+ and altering cholesterol levels) and significantly less expensive than NR or NMN.
Sustained-release niacin – This form was invented to avoid the flushing effect of nicotinic acid by releasing niacin over the course of 12+ hours. Unfortunately, it was soon discovered that sustained-release niacin is associated with high rates of hepatotoxicity (liver damage.)
Extended-release niacin – In this form, niacin is released for around 8 hours. Fortunately, this version does not seem to cause liver toxicity and it doesn’t cause nearly as much flushing as regular nicotinic acid. The only problem is that manufacturers sometimes mislabel their niacin products, calling them extended-release even if they are sustained-release.
Inositol hexanicotinate – This form is slowly broken down in the body and takes 6-12 hours to get absorbed. Unfortunately, it does not release enough niacin for the flushing and cholesterol-lowering effect. On top of that, this form, if taken in high doses over an extended period of time, can cause significant liver damage.
NR (nicotinamide riboside) – This relatively new form may be superior to those previously mentioned in that it has much less potential for harm. NR also does not cause flushing, but does not have the same effects on cholesterol levels as nicotinic acid.
Severe vitamin B3 deficiency is called pellagra. The main symptoms of pellagra are “the three Ds”: dementia, diarrhea, and dermatitis (in severe cases, a fourth D can be added, death). Although it is unlikely that you will ever experience such a deficiency, an inadequate supply of dietary niacin can still lead to many health problems. The most common signs of niacin deficiency include:
fatigue
exercise intolerance
depression
accelerated skin aging
bright red tongue
a pigmented skin rash following sun exposure
impaired circulation
headaches
impaired memory
hallucinations
oral ulcers
tongue swelling
diarrhea
Keep in mind that these signs are just indications of deficiency. The fact that you experience some of them does not necessarily mean that you need more vitamin B3. On the other hand, some people may have a deficiency even though they are completely asymptomatic.
With that said, if you experience many or most of these symptoms, there is a high chance you are not getting enough niacin. The more of these symptoms you experience and the more severe they are, the more likely you are deficient.
How much niacinamide should you take?
The RDA (recommended daily allowance) for vitamin B3 is 16 mg for men and 14 mg for women. This amount is, in most cases, sufficient to prevent symptoms of deficiency.
However, that does not mean you can not get even more benefits from a higher amount of niacinamide. The benefits mentioned above in this article often have to do with much higher doses of vitamin B3.
Alcohol, sun exposure, digestive disorders, stress, and a few other factors increase your need for niacin.
Niacinamide is safer than nicotinic acid in many ways, but taking high doses of this form is not as effective for increasing healthspan as taking other forms. The main benefit of niacinamide is to correct vitamin B3 deficiency.
If you choose to take niacinamide to raise NAD+ levels, 100 mg appears to be the optimal amount. Any more than that will probably not get converted unless you have an abnormally high amount of the NAMPT enzyme.
As for NR and NMN, 1000 mg per day seems to be the optimal amount. Do not take higher doses than 3000 mg of niacinamide, NR, or NMN without consulting your doctor!
Regardless of which form you decide to take, start low and gradually increase your dose.
Food sources of vitamin B3
Legumes, nuts, fish, mushrooms, certain vegetables and organ meats are the richest sources of vitamin B3.
Grains and seeds are considered a great source of niacin. Unfortunately, 85-90% of the niacin in whole grains and 40% of the niacin in seeds are bound and cannot be absorbed. However, you can release some of the niacin by sprouting and fermenting these foods.
Your body can also synthesize niacin from protein (specifically, from an amino acid called L-tryptophan. However, other nutrients are required for this conversion. Specifically, you need sufficient amounts of vitamin B6, iron, and riboflavin. This means that even if you do not get enough vitamin B3 from food, you may not suffer from a niacin deficiency if you consume a high amount of the three nutrients. The easiest way to find out how much niacin (and other nutrients) you are getting in your diet is with Cronometer.com – the app is free and allows you to track all vitamins, minerals, and more.
Best time to take niacinamide
Always take vitamin B3 supplements with a meal, and divide the dose evenly across each meal. Taking the supplement on an empty stomach may cause stomach upset.
If you decide to take niacinamide, take it either in the morning or the early afternoon. This is when the enzyme called NAMPT is at its peak. NAMPT is needed to convert niacinamide into NMN.
For other forms of niacin, it does not matter much whether you take them in the morning or in the evening although taking the supplement after dinner is likely the best option.
Interactions with other supplements
TMG TMG (trimethylglycine) can protect against potential liver toxicity caused by vitamin B3 supplements. For optimal effects, pair niacinamide with an equal amount of TMG.
Glycine Glycine may have a similar effect as TMG but if you have money to afford TMG, it is more useful than glycine in this case.
Resveratrol Resveratrol helps niacinamide turn into NMN by boosting an enzyme called NAMPT. NAMPT is needed for the conversion.
CoQ10 Combining CoQ10 with any form of vitamin B3 can improve mitochondrial performance.
Statins Taking vitamin B3 along with some statins may increase the risk of muscle damage in some people.
Alcohol Consuming alcohol and vitamin B3 together might lead to liver damage.
Where to buy niacinamide
Amazon seems to be the best option for ordering niacinamide supplements in most countries. They offer some very affordable products that are backed by many positive reviews. Also, you can choose from a wide range of brands there without having to spend time searching through other markets on the internet.
The most important thing you should pay attention to is that some brands display the dosage per serving and not per pill or capsule. Therefore, you may accidentally buy something that is less potent than you intended. Do not fall for this marketing trick.
FAQ
Vitamin B3 can be taken daily and does not need to be cycled.
Yes. Unless you get the flush when falling asleep, niacin won’t impact your sleep in any negative way. Taking it in the evening may actually be preferred.
Niacin supplements do not expire. They can, however, lose potency over time. To minimize this, keep your supplements in a cold, dark, and dry place.
No, nicotinamide does not cause a niacin flush. Only nicotinic acid does.
Niacin has a half-life of 20-45 minutes. Therefore, it takes about 2-6 hours to leave your system.
Liver damage is the primary and most notable symptom of toxicity.
No, it doesn’t. The supplement does not interfere with fasting in any notable way.
References
Most of the information provided in this guide is based on scientific research that can be found and verified in the PubMed medical library. We excluded from consideration studies that are either confounded or have a high conflict of interest.
Anecdotal evidence (from reports on Reddit, YouTube, and other sources) is also taken into account unless it contradicts scientific research.
