Nicotinamide Riboside side effects and experiences

In a clinical study, researchers found that a daily dose of 500 mg Nicotinamide Riboside (NR) led to an average increase in NAD⁺ levels of 90% after four weeks compared with the placebo group¹. Those figures are striking, but they also raise logical questions: is NR actually safe? Are there side effects? And what do people who already use it think?

In this article, we look at possible side effects, share users’ experiences, and discuss what science has said so far about the safety of NR—so you can make an informed choice yourself.

What is Nicotinamide Riboside good for?

Nicotinamide Riboside is a form of vitamin B3² and a direct precursor of NAD⁺¹. This coenzyme is found in all your cells and is involved in hundreds of processes, from energy production to DNA repair³.

In research, raising NAD⁺ levels is associated with:

• Better energy balance in cells
• Supporting cellular repair
• Possibly slowing age-related decline⁴
  
  

Because NAD⁺ levels decline as you get older, more and more people—from athletes to biohackers—are looking at NR as a way to counter this decline.

Nicotinamide Riboside side effects

The good news: multiple human studies show that NR is generally well tolerated, even at higher doses⁵. No serious side effects have been found in healthy adults who used NR within the recommended amounts.

Still, some users report mild, temporary complaints such as:

• Fatigue or a slight sluggish feeling
• Nausea or an unsettled stomach
• Headache
• Mild gastrointestinal discomfort
  
  

These complaints are not common and usually go away on their own if you stop or lower the dose. Because everyone responds differently, it remains wise to stay alert to signals from your body.

Experiences with NR

Experiences vary. Many users describe that after several weeks of consistent use:

• Having more physical energy during work or sports
• Recovering faster after intense training
• Being mentally sharper, with more focus
  
  

For example, one user described that “after three weeks of NR, he noticed he got tired less quickly while running and had less trouble with heavy legs after a long workday.”

Others notice more subtle effects, such as a steadier energy level throughout the day. There are also people who report not experiencing any difference, even after a longer period. This shows that results are personal and depend on factors such as age, lifestyle, and diet.

What do scientific studies say about safety?

The European Food Safety Authority (EFSA) evaluated NR chloride and concluded that it is safe for healthy adults when used up to 300 mg per day in dietary supplements⁶. For pregnant and breastfeeding women, a maximum of 230 mg per day is recommended.

In a clinical study in middle-aged and older adults, 1000 mg NR per day for eight weeks led to a significant increase in NAD⁺ levels, without serious side effects⁵. Most participants reported no complaints at all.

Preclinical animal research also found no serious safety concerns, although it remains important to be cautious about directly translating animal results to humans.

Who should not use Nicotinamide Riboside?

Although NR is considered safe for most healthy adults, there are groups for whom caution is advised:

• Pregnant women and women who are breastfeeding – use only in consultation with a doctor
• People with liver conditions – due to the role of vitamin B3 in the liver
• People taking medication – especially with medicines that affect the liver
  
  

Unsure? Always consult a medical professional before you start.

How can you minimize side effects?

Want to try NR, but start cautiously? These tips can help:

1. Start low – start with 150 mg (1 capsule) per day
2. Take it with a meal – this reduces stomach discomfort
3. Increase slowly – increase to 300 mg per day after a week or two
4. Consider combining with TMG – supports methylation, which may help NR conversion⁷
   

This approach gives your body the chance to get used to it calmly and makes it easier to see whether NR suits you.

Sources

1. Martens CR et al. Chronic nicotinamide riboside supplementation elevates NAD+ in healthy middle-aged and older adults. Nat Commun. 2018;9:1286.
   
   
2. Bogan KL, Brenner C. Nicotinic acid, nicotinamide, and nicotinamide riboside: A molecular evaluation of NAD+ precursor vitamins in human nutrition. Annu Rev Nutr. 2008;28:115-30.
   
   
3. Yoshino J et al. Nicotinamide mononucleotide, a key NAD+ intermediate, treats the pathophysiology of diet- and age-induced diabetes in mice. Cell Metab. 2011;14(4):528-536.
   
   
4. Trammell SA et al. Nicotinamide riboside is uniquely and orally bioavailable in mice and humans. Nat Commun. 2016;7:12948.
   
   
5. Airhart SE et al. An open-label, non-randomized study of the pharmacokinetics of nicotinamide riboside and its effects on blood NAD+ metabolism in healthy subjects. PLoS One. 2017;12(12):e0186459.
   
   
6. EFSA Panel on Nutrition, Novel Foods and Food Allergens. Safety of nicotinamide riboside chloride as a novel food pursuant to Regulation (EU) 2015/2283. EFSA Journal. 2019;17(12):5905.
   
   
7. Newmedix – Anti-aging with NAD and Resveratrol