NAD Precursors (NMN, NR) Simply Explained

1. What It Is About

NAD precursors are building blocks from which the body produces a substance called nicotinamide adenine dinucleotide. This substance is abbreviated as NAD+. NAD+ is a helper in every cell. It is needed when the body gains energy, repairs genetic material and cells renew themselves. Two of these building blocks are well known: nicotinamide mononucleotide, abbreviated NMN, and nicotinamide riboside, abbreviated NR. Both can be taken as capsules. In the body, the cell converts them into NAD+. This occurs via a specific pathway called recycling. Small amounts of these building blocks also occur in foods, for example in milk, yeast and some vegetables. However, these amounts are much smaller than those in capsules. Researchers are interested in whether more NAD+ in the body is also associated with better movement, less fatigue or less inflammation. NAD+ is measured in blood or tissue samples. Such measurements are elaborate and vary from study to study.

2. What Studies Show

The NAD+ value in blood has been measured most frequently. It rose measurably in several studies. In one study, 80 healthy middle-aged adults took NMN in different amounts or a placebo for 60 days 1. The NAD+ value in blood rose, and the larger the amount, the more pronounced the increase. Blood sugar regulation and physical well-being showed no discernible effect in this short period.

Movement was also tested in older people. In one study, healthy older men took NMN for 6 or 12 weeks 3. The NAD+ value in blood rose. Walking speed and left-hand grip strength improved slightly. The difference was small and could have occurred by chance. In another study with 108 older adults, NMN was tested for 12 weeks 5. Participants were somewhat quicker at rising from sitting and felt less tired during the day. The difference was particularly clear when the capsule was taken in the afternoon.

Blood measurements showed a different picture. In a small study, 22 healthy older adults took NR for 6 weeks 6. Afterwards, tiny vesicles carrying features of nerve cells were examined in the blood. More NAD+ was measurable in them, and certain proteins involved in inflammation and insulin action were lower. What this means for thinking and memory has not been clarified.

Statements on tolerability are clearest. In a study with Parkinson’s patients, NR was also well tolerated in larger amounts, no serious side effects occurred, and the NAD+ value in blood rose markedly 4.

3. What Remains Unclear

Many studies are small and short. They often last only a few weeks to months, and not all compare against a placebo. The rise in NAD+ in blood is a measurement value and not proof that a person feels better or that a disease takes a different course. A small change appeared in muscle strength 3. Other muscle measurements remained unchanged in another study 2. Whether NR and NMN differ in their effects has hardly been compared. Studies lasting a year or longer are still pending. The transfer of animal and cell experiments to humans is also an open question, because NAD+ metabolism and ageing proceed differently in animals and humans.

4. What This Means in Everyday Life

Taking NR and NMN reliably raises the NAD+ value in blood. This is well documented and has also been shown to be well tolerated over short periods 4 7. Whether this measurement value translates into everyday life, movement or fatigue is not established: the indications are small and not consistent. The studies mostly measure only the intermediate value in blood, not what people themselves experience. Anyone wanting to know whether NAD precursors change anything in a specific complaint will not yet find a reliable answer. The next step would be to clarify whether long-term intake produces any effect at all and whether NR and NMN differ in this regard.

All details with study numbers and sources: detailed page on NAD precursors (NMN, NR). For children: NAD precursors (NMN, NR) for children.