NMNH dosage and evidence

Raises NAD in cells and mouse tissue faster and higher than NMN, by a route that skips two slow enzyme steps. In the same experiments it slowed the cell's main sugar-burning steps, stopped cells dividing and held back cell growth in a dish. No person has been given it in a published study.

NMNH is the reduced form of NMN. It is the most interesting molecule in this batch, for reasons that cut both ways.

Two teams made it separately and published within weeks of each other in 2021. Both found the same headline. NMNH raises NAD higher and faster than NMN or NR in cells. It does this by a route that skips both NRK and NAMPT and goes straight to the last step. In mice, a single dose caused a fast, lasting jump in NAD in the blood. NAD rose in the liver, kidney, muscle, brain, brown fat and heart, but not in ordinary white fat. In a dish, it also cut damage and sped up repair in kidney cells after they were starved of oxygen.

Then comes the other half, from the second team, in the same year. A broad chemical scan showed NMNH slowed the cell's main sugar-burning steps. In a dish, it stopped cells dividing and held back cell growth. The mice did not lose weight. That is the only safety result in living animals in the paper's summary.

That mix is exactly what you would want to understand fully before selling it: a strong NAD booster that also slows how cells make energy and grow. It is being sold. There is no study of how the human body handles it, no safety study in people, and no human study of any kind.

The cell growth finding also runs into the open cancer question that hangs over this whole pathway. Slower cell growth could be read as a good thing. Or it could be a sign the product is doing something big to how cells work that nobody has studied in a person. Both readings are guesses right now.

There is no human evidence for NMNH. No study of how the body handles it, no safety study, no trial. That is why this page has no human evidence section, and it is the most important fact about it.

What makes NMNH worth a page anyway is this. Two teams made it and tested it separately in 2021. They agreed on how strong it is and disagreed about nothing. One of them also ran a broad chemical scan. It found the product slowed the cell's sugar-burning steps and slowed cell growth. That second half is not an attack from a rival team. It sits in the same paper as the strength result, from a team that clearly found the molecule interesting.

The balance argument is worth stating, because it is the reason not to treat reduced forms as a simple upgrade. NMN and NR raise NAD. NMNH comes in as the reduced form and raises NADH too. The balance between NAD and NADH helps control how cells burn fuel. So a product that moves that balance is not neutral for energy use. In the one experiment that measured it, energy use went down.

Anyone selling NMNH on the fold-change number is quoting the first half of a paper. The second half is a list of things the product slowed down.

Almost all consumer writing about this pathway blends three kinds of claim into one. Keeping them apart is most of the work. A blood marker claim says a product raises NAD in the blood. That is easy to show, and for several of these products it is simply true. A middle claim says it moves something between a blood marker and a symptom, such as how stiff the arteries are. A health claim says a person walks further, remembers more, gets fewer cancers or lives longer. A product can be solid on the first kind and have nothing at all on the third. That is where most of this pathway sits. No published study in people of any NAD booster has shown a real health benefit, with one exception on this list. That exception is nicotinamide in skin cancer. It works by helping sun-damaged skin repair its DNA, not through anything to do with ageing.