Nicotinamide Riboside Side Effects


What is Nicotinamide Riboside (NR)?

Nicotinamide Riboside (NR) is a naturally occurring form of vitamin B3, a crucial nutrient in various foods, including milk, yeast, and certain vegetables [1]. Often recognized as a “miracle molecule,” NR is vital in maintaining overall health and well-being.


The importance of NR lies in its function as a precursor to Nicotinamide Adenine Dinucleotide (NAD+), a coenzyme present in every cell of our bodies. NAD+ is essential for various biological processes such as energy production, DNA repair, cell survival, and even the regulation of circadian rhythms.

As we age, the NAD+ levels in our bodies begin to decline. This can lead to cellular aging, metabolic disorders, and other health problems.

NR supplementation is considered a powerful strategy to boost NAD+ levels in the body, promoting cellular health, improving energy metabolism, and potentially slowing down aging.

Research has shown that NR is the most efficient precursor to NAD+ compared to other compounds. In terms of efficiency, studies have suggested that NR may be the best-known precursor to NAD+ [2].

Nicotinamide riboside was actually discovered a long time ago. In 1944, it was described as a “growth factor” for a type of bacterium that lives in the blood. Among the precursors, NR was said to cause the most rapid growth of the bacterium [3].

NR is available as a supplement, marketed under the brand name Niagen, and molecularly, it is the same as NR found in dietary sources. Similar to how a Japanese company owns the process for synthesizing ubiquinol, the best form of ubiquinone/CoQ10, there is only one company that holds the patents for the synthesis of NR. ChromaDex, through exclusive licensing agreements with academic institutions, owns the patented synthesis processes. They began producing and selling NR under the brand name Niagen in 2013.

Various supplement manufacturers license NR from ChromaDex, and it is marketed under different brand names. These supplements have become increasingly popular, and some of the notable brands include Tru Niagen, HPN Nutraceuticals, and Life Extension NAD+ Cell Regenerator. It is important to note that these brands use the same source for the active ingredient, ChromaDex [4].

Side Effects

While NR presents promising benefits, it is essential to understand its potential side effects and the correct dosage to ensure safety and efficacy.

As with any supplement, it's important to be aware of possible adverse reactions that may result from taking them. Regarding the side effects of nicotinamide riboside, much of the findings from studies have been positive.

A review published in 2013 analyzed prior animal model studies and suggested positive properties of NR. It was found to be insulin sensitizing, causing nicotinamide riboside headache, enhancing to exercise, resisting the negative effects of a high-fat diet, and neuroprotecting [5]. However, it is crucial to note that these studies are based on animals, and more research is needed to draw definitive conclusions.

A study published in Human and Experimental Toxicology, in 2016, specifically examined the safety of nicotinamide riboside. The study used several methods to assess its safety, including bacterial reverse mutagenesis assay, in vitro chromosome aberration assay, in vivo micronucleus assay, and acute 14 and 90-day rat toxicology studies. The study found that Niagen was not genotoxic and its toxicity and side effects were similar to regular nicotinamide [6].

The study identified a dosage of 1,000 mg/kg/day as the lowest observed adverse effect level for NR. The study did not state the exact overdose symptoms, but the liver, kidney, ovaries, and testes were the "target organs" for toxicity. Presumably, the side effects were related to one or more of those organs. The study also determined a no observed adverse effect level of 300 mg/kg/day [6].

Considering that the dosage for humans would be much lower, based on body weight, these findings provide reassurance about the safety of NR. Many Niagen supplements on the market are 250 mg per capsule, with an instructed serving size of 1 or 2 capsules per day. To reach a dosage of 20,400 mg per day, which would be equivalent to the 300 mg/kg level, one would have to take approximately 40 times the recommended dosage [6].

Currently, there are over 150 articles on PubMed that mention nicotinamide riboside, and there are no reports of serious side effects [7].

However, it is important to note that individuals with a methylation defect or those on certain medications may have different reactions to NR. There have been reports of neuropathy, fatigue, and pain in individuals with methylation defects. Additionally, one individual reported peripheral neuropathy, joint, and muscle pain after taking NR while on levothyroxine, a medication for treating hypothyroidism. It is always recommended to consult with a healthcare professional before taking any supplement.



In conclusion, Nicotinamide Riboside (NR) is a naturally occurring form of vitamin B3 that plays a crucial role as a precursor to NAD+. NR supplementation is considered a powerful strategy to boost NAD+ levels and promote cellular health. While generally safe and well-tolerated at recommended dosages, individuals may experience mild and temporary side effects suchas gastrointestinal discomfort or flushing. However, more research is needed to fully understand the long-term effects and potential side effects of NR supplementation.

It is always important to consult with a healthcare professional before starting any new supplement, especially if you have any underlying health conditions or are taking medications. They can provide personalized advice and help determine the appropriate dosage for your specific needs.

Overall, the use of NR as a supplement shows great promise in supporting cellular health and potentially slowing down the aging process. However, more research is needed to fully understand its effectiveness, safety, and optimal dosage.