Guide
Who should not take nicotinamide riboside (NR)?
The controlled trials behind nicotinamide riboside's safety data excluded pregnant and breastfeeding people, children, and anyone with liver disease, kidney disease, diabetes, or a history of alcohol or drug abuse — so there's no trial evidence covering those groups either way.
The controlled trials that established nicotinamide riboside's safety profile did so in carefully screened, generally healthy adults — which means several groups were excluded from that data entirely, not shown to be safe or unsafe. Pregnant people, children, and anyone with liver disease, kidney disease, or diabetes fall into that gap.
| Situation | Why it matters |
|---|---|
| Pregnant or breastfeeding | No trial reviewed here included pregnant or breastfeeding people; the largest trial specifically required non-pregnant, non-breastfeeding status |
| Children | No trial reviewed here included children or adolescents |
| Liver disease | Explicitly excluded from the largest safety trial — no trial data covers this group |
| Kidney (renal) disease | Explicitly excluded from the largest safety trial — no trial data covers this group |
| Diabetes | Explicitly excluded from the largest safety trial — no trial data covers this group |
| History of alcohol or drug abuse, or heavy current alcohol use | Explicitly excluded from the largest safety trial |
| Taking a blood-pressure or cholesterol-lowering medication | Excluded from the largest safety trial — no trial data covers this combination |
Pregnancy and breastfeeding
No trial we reviewed included pregnant or breastfeeding people. The largest safety trial (140 adults) specifically required participants to be non-pregnant and non-breastfeeding, and required women of childbearing potential to use medically approved contraception for the study's duration (PMID 31278280). That's a standard research-safety precaution, and it means there's no trial evidence either way for this group — ask a doctor before use.
Children
No trial reviewed here enrolled children or adolescents; every trial recruited adults, generally in their 40s and older. There's no dosing or safety research to draw on for children, so a pediatrician's input is the appropriate substitute for research that doesn't exist.
Liver disease, kidney disease, or diabetes
The largest safety trial explicitly excluded anyone with a history of liver disease, kidney (renal) disease, or diabetes (PMID 31278280). That's an absence of evidence, not evidence that nicotinamide riboside is unsafe for these conditions — but it does mean the reassuring safety data from these trials doesn't extend to them. Ask a doctor before use if any of these apply to you.
Heavy alcohol use or a history of substance use
The same trial excluded people who drank more than 2 alcoholic servings a day or had a history of drug or alcohol abuse in the past year (PMID 31278280). As with the conditions above, that's a screening criterion, not a documented danger — but it means this group isn't represented in the safety data either.
Taking a blood-pressure or cholesterol medication
People taking antihypertensive or lipid-lowering medications were excluded from the largest safety trial (PMID 31278280). See nicotinamide riboside (NR) and medications: what to check for more on this gap and what it means for combining nicotinamide riboside with a prescription medication.
Who this doesn't apply to
Outside the groups above, the trials reviewed here — generally healthy adults without these conditions, at doses up to 2,000 mg/day for up to 12 weeks — don't identify a documented safety reason to avoid nicotinamide riboside. That's separate from whether it does anything measurable, covered in nicotinamide riboside (NR) benefits: what the research does and doesn't show.
Questions people ask
Who should not take nicotinamide riboside?
Pregnant or breastfeeding people, children, anyone with liver disease, kidney disease, or diabetes, anyone with a recent history of heavy alcohol or drug use, and anyone taking a blood-pressure or cholesterol medication should check with a doctor first — none of these groups is represented in the controlled safety trials.
Can nicotinamide riboside cause liver damage?
No trial reviewed here reported liver injury from nicotinamide riboside, but the trials also excluded people with existing liver disease, so there's no data on that specific group. Anyone with liver concerns should ask a doctor before starting.
Is nicotinamide riboside safe for the kidneys?
People with kidney disease were excluded from the largest safety trial, so there's no direct trial evidence either way for that group. Ask a doctor before adding nicotinamide riboside if you have reduced kidney function.
Related reading: nicotinamide riboside (NR) side effects, nicotinamide riboside (NR) and medications: what to check, and nicotinamide riboside (NR) benefits: what the research does and doesn't show.
Sources
- Safety and Metabolism of Long-term Administration of NIAGEN (Nicotinamide Riboside Chloride) in a Randomized, Double-Blind, Placebo-controlled Clinical Trial of Healthy Overweight Adults A 2019 randomized, placebo-controlled trial of 140 adults found nicotinamide riboside raised blood NAD+ dose-dependently at 100-1,000 mg/day over 8 weeks with no reports of flushing and no rise in LDL cholesterol or homocysteine, unlike the other forms of vitamin B3.
- A randomized placebo-controlled clinical trial of nicotinamide riboside in obese men: safety, insulin-sensitivity, and lipid-mobilizing effects A 2018 trial of 40 obese men given 2,000 mg/day of NR for 12 weeks found no improvement in insulin sensitivity, glucose metabolism, or body composition compared with placebo, though it was safe and well tolerated.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.