Nicotinamide Riboside

What is nicotinamide riboside and what does it do in the body?

Nicotinamide riboside is a precursor of nicotinamide adenine dinucleotide (NAD⁺), an important cofactor that takes part in cellular energy metabolism; it has shown many metabolic benefits in laboratory animal studies. Its first clinical trial was conducted in 2016, and since then many studies investigating benefit in metabolic health and serious diseases have been published. ^[1] Dollerup and colleagues describe NR as a member of the vitamin B3 family. ^[4] EFSA, on the other hand, stated that synthetic NR chloride contributes to the body’s nicotinamide pool and is a bioavailable source of nicotinamide (a form of niacin). ^[8]

What is measured in human studies is the rise in blood or muscle NAD⁺ metabolites after supplementation. Results in animal studies have not translated to humans in the same way; the review by Damgaard and Treebak, looking at published human studies, notes that there is a tendency in the literature to overstate the importance of findings. ^[1]

Does nicotinamide riboside raise NAD levels?

Yes; this is the most consistent human finding. In the 8-week, double-blind, placebo-controlled RCT by Conze and colleagues, overweight but healthy adults received 100, 300, or 1,000 mg of NR or placebo. Within two weeks, whole-blood NAD⁺ level rose in a dose-dependent manner: 22% with 100 mg, 51% with 300 mg, and 142% with 1,000 mg; the rise was maintained throughout the study. No flushing was reported, side effects did not differ significantly between the NR and placebo groups; NR did not raise LDL cholesterol and did not disrupt one-carbon metabolism. ^[3] The study was funded by an NR manufacturer; two of the authors are employees of the manufacturer, and one author is the inventor of intellectual property licensed to the company and a scientific adviser. ^[3]

In the 6+6-week double-blind, placebo-controlled crossover study by Martens and colleagues in healthy adults aged 55–79, 1,000 mg of NR per day was well tolerated and stimulated NAD⁺ metabolism; the authors interpreted the findings on blood pressure and arterial stiffness as exploratory. 30 people were randomized in the study, and 24 completed it. The authors reported no competing interests; however, according to the full text, the study capsules and partial funding were provided by an NR manufacturer, and the main funding was NIH grants. ^[2] In the 20-person pilot study by Orr and colleagues in people with mild cognitive impairment, blood NAD⁺ rose 2.6-fold with a target dose of 1 g per day. ^[6] The rise in blood NAD⁺ is common to all these studies; whether the rise translates into a clinical outcome is a separate question.

Does NR improve metabolic health and insulin sensitivity?

In the investigator-initiated, randomized, placebo-controlled study by Dollerup and colleagues, 40 healthy sedentary men (aged 40–70) with a body mass index above 30 received 1,000 mg of NR twice daily or placebo for 12 weeks. Insulin sensitivity measured by hyperinsulinemic euglycemic clamp, endogenous glucose production, and glucose utilization and oxidation did not improve with NR; resting energy expenditure, lipolysis, lipid oxidation, and body composition also did not change. No serious side effects were observed, and safety blood tests were normal. ^[4]

In the 6-week double-blind, placebo-controlled crossover study by Remie and colleagues, 13 healthy overweight or obese volunteers received 1,000 mg of NR per day. NAD⁺ synthesis markers rose in skeletal muscle; the lean mass proportion rose slightly (62.65% and 61.32%; change 1.34% ± 0.50%; p = 0.02) and sleeping metabolic rate rose; however, no effect was found on insulin sensitivity, mitochondrial function, liver and intramuscular fat accumulation, cardiac energy status, ambulatory blood pressure, inflammation markers, and energy metabolism. ^[5] That is, changes were seen in some intermediate metabolites such as muscle acetylcarnitine; no difference emerged in health-related outcome measures.

Does NR affect muscle strength and aging?

The 2025 systematic review and meta-analysis by Prokopidis and colleagues examined RCTs comparing NR or NMN with placebo; the mean age of participants ranged from 60.9 to 83. For NMN, no significant effect was found on skeletal muscle index, grip strength, gait speed, and the five-times sit-to-stand test. The results reported for NR are limited: in people with peripheral artery disease, 6-minute walking distance was longer; in people with mild cognitive impairment, however, short physical performance battery scores were lower and the five-times sit-to-stand test was slower. The authors concluded that current evidence does not support NMN and NR supplementation for preserving muscle mass and function in adults with a mean age over 60. ^[7]

The review by Damgaard and Treebak, which critically examined 25 human studies, reports that oral NR supplementation showed few clinically meaningful effects; the authors nonetheless say that NR may play a role in reducing inflammatory conditions and shows potential in various serious diseases. ^[1] It has not been shown that aging slows or lifespan lengthens in humans; this claim rests on laboratory animal data (grade E).

Does NR affect blood pressure and arterial stiffness?

Martens and colleagues presented the potential of NR to reduce systolic blood pressure and aortic stiffness in healthy adults aged 55–79 as the most promising hypothesis for future studies; this was an exploratory analysis, and the study targeted NAD⁺ metabolism. ^[2] In the study by Remie and colleagues, however, no NR effect on ambulatory blood pressure was found. ^[5] The blood pressure signal is small, exploratory, and inconsistent; the evidence grade is D.

Does NR affect memory and cognition?

Orr and colleagues randomized 20 older adults with mild cognitive impairment; in the 10-week pilot study in which the dose was escalated to 1 g per day, the primary outcome was the change in Montreal Cognitive Assessment (MoCA) score. MoCA and other neurocognitive and psychometric measures stayed stable throughout the study. NR reduced cerebral blood flow in some brain regions; the authors noted that this would not survive multiple-comparison correction. In the placebo group, gait speed increased through a practice effect and did not change in the NR group. The study was conducted with the support of a company that supplied NR and placebo; one author is the inventor of intellectual property on NR uses and is the company’s scientific adviser and a shareholder, and did not take part in design and conduct. ^[6] The authors noted that a larger and longer trial is needed.

Does NR work in Parkinson’s disease?

The largest and longest human study for NR is NOPARK: a randomized, double-blind, placebo-controlled phase 3 study conducted at 11 centers in Norway enrolled 410 people aged 35 and over with early-stage Parkinson’s disease diagnosed within the last 2 years (393 in the main analysis); participants received 500 mg of NR or placebo twice daily for 52 weeks. The MDS-UPDRS total score rose by 2.45 points in the NR group and fell by 0.27 points in the placebo group; the adjusted difference was 2.72 points (95% CI 0.47–4.98; p = 0.02) and favored placebo. There was no significant difference in four of the five prespecified key secondary measures; non-motor symptom burden worsened more in the NR group (NMSS difference 4.22 points; 95% CI 1.07–7.37). Serious adverse events were seen in 17 of 205 people (8.3%) in the NR group and 29 of 205 people (14.1%) in the placebo group. The authors concluded that the findings do not support NR as a disease-modifying treatment in Parkinson’s disease. According to the disclosure statement, two authors own patents related to the use of NR in Parkinson’s treatment and licensed to an NR manufacturer. ^[11]

Is NR safe? The EFSA assessment

In the study by Dollerup and colleagues, no serious side effects were seen at a dose of 2,000 mg per day for 12 weeks. ^[4] In the 8-week study by Conze and colleagues, there was no difference in side effects between NR and placebo at doses of 100, 300, and 1,000 mg. ^[3] These data in healthy volunteers or those with metabolic risk are at the level of weeks; in the 52-week NOPARK study, serious adverse events were 8.3% in the NR group and 14.1% in the placebo group, but clinical outcomes were worse than placebo. ^[11]

In its 2019 opinion, EFSA’s Panel on Nutrition, Novel Foods and Food Allergens (NDA) evaluated NR chloride, a synthetic nicotinamide riboside, as a food supplement for healthy adults at up to 300 mg per day. The production process, composition, and stability raised no safety concern; there was no genotoxicity concern; human studies raised no safety concern. The proposed maximum use level corresponds to an amount of nicotinamide six-fold below the established tolerable upper intake level for nicotinamide in adults. The margin of safety of 70 derived from rat and dog repeated-dose toxicity studies was found adequate for the adult population other than pregnant and breastfeeding women; the margin of 76 derived from the developmental toxicity study in rats was considered inadequate for these two groups because it is below 100. The panel concluded that NR chloride is safe for healthy adults other than pregnant and breastfeeding women, and that for pregnant and breastfeeding women, intake up to 230 mg per day is safe. ^[8]

In EFSA’s 2021 extension-of-use opinion, the panel concluded that the safety of general population use of NR chloride at up to 300 mg per day in “meal replacement products” and “nutritional drink mixes” could not be established; the reason was the absence of an upper intake level for nicotinamide for infants and the narrow margin between the estimated infant intake and the reference values. In foods for special medical purposes and total diet replacement for weight control (up to 500 mg per day, in adults), this amount corresponds to 210 mg of nicotinamide and is below the current upper intake level for nicotinamide in adults of 900 mg/day; the panel found NR as safe as pure nicotinamide in these uses. The same panel drew attention to experimental data indicating that intakes of nicotinamide or its precursors far above physiological requirement may lead to side effects and noted that reassessment of the upper intake level for nicotinamide may be necessary. ^[9]

What is the regulatory status in Türkiye and Europe?

Türkiye. Nicotinamide riboside falls under the dietary supplements legislation of the Ministry of Agriculture and Forestry; it is not a drug. In the September 21, 2026 version of the Ministry’s Restricted Substances List for Dietary Supplements, the “Nicotinamide Riboside” row states chemical synthesis as the source; the upper limit in the age 11 and over column is 300 mg/day, with a publication date of July 9, 2018. ^[10] The list also has beta-nicotinamide mononucleotide (NMN) in a separate row: chemical synthesis, 50 mg/day, publication date June 4, 2021. ^[10] The upper limits of the two substances are written in separate rows and are not equivalent to each other.

Europe. In Europe there are two EFSA scientific opinions: the 2019 opinion found use as a food supplement at up to 300 mg per day safe for healthy adults (excluding pregnant and breastfeeding women); the 2021 opinion stated that safety was not established for meal replacement products and nutritional drink mixes. ^[9] This guide does not recommend products or places of supply.

Evidence table: claim, population, and limits

This guide does not recommend personal doses; the numbers above are a report of study results.