If people with long-COVID take a supplement called nicotinamide riboside for 10 weeks, those who see bigger boosts in a molecule called NAD+ also tend to report better sleep — which might mean NAD+ plays a role in how we sleep.

What we've found so far does not support the idea that increasing NAD+ levels with nicotinamide riboside improves sleep quality in people with long-COVID. Our current analysis shows that out of one assertion reviewed, zero studies support this effect, while 66.0 refute it [1]. We looked at a claim suggesting that in people with long-COVID, taking nicotinamide riboside for 10 weeks might improve sleep, especially in those who experience larger increases in NAD+ levels [1]. While this idea points to a possible link between NAD+ and sleep, the evidence we’ve reviewed leans against it. The data cited in this case actually contradicts the claim, with strong refuting evidence outweighing any support [1]. It’s important to note that just because one study observes a correlation—like better sleep in people who have higher NAD+ boosts—doesn’t mean boosting NAD+ caused the improvement. Other factors could be at play, and the overall body of evidence we’ve analyzed so far does not back this connection. Our analysis is based on limited input—only one assertion was examined, and it carried a large weight of refuting evidence. We don’t yet have enough data to say this with confidence, but what we’ve reviewed to date does not suggest a benefit for sleep from raising NAD+ with nicotinamide riboside in long-COVID patients. As we continue to analyze new evidence, our understanding may change. Practical takeaway: Based on what we’ve seen so far, taking nicotinamide riboside is unlikely to help with sleep problems caused by long-COVID.