Nicotinamide riboside side effects
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Nicotinamide Riboside Side Effects: Safety in Human and Animal Studies
Human Clinical Trials: Safety and Tolerability of Nicotinamide Riboside
Multiple human clinical trials have shown that nicotinamide riboside (NR) is generally safe and well-tolerated at commonly used doses. Studies involving healthy overweight adults and obese men found no significant differences in adverse events between NR and placebo groups, even at doses up to 2000 mg per day for 8 to 12 weeks. There were no reports of serious side effects, such as flushing, changes in cholesterol, or disruptions in metabolism, and safety blood tests remained normal throughout the studies 35. Reviews of human supplementation trials also confirm that NR has displayed few clinically relevant side effects, with most participants tolerating the supplement well .
Animal Studies: High-Dose Toxicity and Organ Effects
In animal studies, NR has shown a similar toxicity profile to nicotinamide, another form of vitamin B3. At very high doses (1000 mg/kg/day and above), NR caused adverse effects in the liver, kidneys, ovaries, and testes in rats. The lowest dose at which adverse effects were observed was 1000 mg/kg/day, while 300 mg/kg/day was identified as a no observed adverse effect level . Additionally, repeated high-dose intravenous administration of NR in rats led to negative effects on the cochlear section of the auditory system, suggesting potential ototoxicity at extreme doses .
Summary of Reported Side Effects
- In humans: No serious adverse events or significant side effects at doses up to 2000 mg/day for up to 12 weeks 345.
- In animals: High doses can cause toxicity in the liver, kidneys, reproductive organs, and may affect hearing 12.
- General conclusion: NR is safe for most people at typical supplement doses, but very high doses may pose risks, especially in animal models 2345.
Conclusion
Nicotinamide riboside is considered safe and well-tolerated in humans at standard supplement doses, with few reported side effects. However, animal studies indicate that extremely high doses can cause organ toxicity and hearing issues. For most people, NR supplementation at recommended levels does not appear to cause significant adverse effects.
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