NAD+: ENERGY, AGE, AND HUMAN STUDIES
NAD+: What it changes inside your cells
Your cells use NAD+ for energy and DNA repair. You’ll see why a blood rise isn’t proof that your health improved.
What NAD+ changes inside your cells
Researchers didn’t invent NAD+. They found it at work in every living cell.
They wanted to learn how cells use food for fuel. They also asked why that work slows with age.
NAD+ helps each cell draw energy from food. It also helps repair damaged DNA.
Some repair jobs use up NAD+. Your body must keep making more.
NAD+ can fall in older tissue. In mice, one protein used more of the supply with age [16].
Two forms can help your body make NAD+. Pills often contain one of those forms.
Researchers test those forms more often than plain NAD+. Your gut doesn’t take in plain NAD+ well.
Studies in people found more NAD+ in blood [11][12][15]. A few groups had small gains in walking or sugar use.
A 2025 review warned against broad claims. Results in mice haven’t always appeared in people [11].
A blood rise is a real finding. It isn’t proof that NAD+ helps people live longer.
You don’t need the chemical codes. Keep your eye on what people felt or could do.
How NAD+ differs from a peptide medicine
NAD+ stands for Nicotinamide Adenine Dinucleotide, oxidized form. Its molecular formula is C21H27N7O14P2. It is a dinucleotide: a nicotinamide mononucleotide (NMN) unit linked to an adenosine monophosphate unit through two phosphate bridges. The pyridine ring of the nicotinamide carries the chemistry that matters — it accepts and donates electrons, cycling between the oxidized form (NAD+) and the reduced form (NADH). The same pair exists in a phosphorylated version (NADP+/NADPH) used in biosynthetic reactions.
NAD+ is a coenzyme, not a peptide; its supplement and prescription forms fall under different rules. Its precursors NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) are what most oral products contain; there is also IV NAD+ used in wellness clinics, though that is compounded and not FDA-approved. There are no brand names to avoid here — generic terms only: NAD+, NMN, nicotinamide riboside.
Unusually for this atlas, NAD+ also has a foothold inside licensed care. NAD+ sits in both settings: Promise Peptides (mypromise.com) prescribes it today, within care that requires a prescription. Each person’s request is assessed by a licensed U.S. clinician, who can decide against prescribing. The service covers U.S. patients only; what can be offered follows state rules and the treatment under consideration. This is a compounded preparation without FDA approval.
How NAD+ moves energy and helps repair DNA
NAD+ has two main jobs inside your cells. Both jobs draw from the same supply.
First, NAD+ picks up energy released from food. It carries that energy into other cell work.
The cell parts that make power need this help. Their work can slow when NAD+ runs low.
Second, DNA repair uses up some NAD+. The same NAD+ can’t simply be carried back.
Several proteins spend NAD+ while repairing broken DNA [14]. They all draw from one supply.
Heavy repair can drain that supply faster. Age may add another drain.
In mice, researchers removed one protein that uses NAD+. The mice then kept more NAD+ as they aged [16].
Their cells also kept making energy better. That mouse finding raised a fair question.
Could the two building forms replace some loss? The human studies below test part of that idea.
They don’t settle the whole question. More NAD+ may not fix the cause of the loss.
You can leave the protein names to the paper. Focus on what changed in the mice and people.
What blood, walking, and heart tests found
The clearest human finding came from blood tests. One pill form raised blood NAD+ as the study amount rose.
The study used 100 to 1000 milligrams a day for 8 weeks. Blood NAD+ rose 22%, 51%, and 142% in 120 adults.
The adults were healthy but overweight. Flushing and other harms weren’t higher than with a look-alike pill called a placebo.
LDL cholesterol didn’t change [15]. The study wasn’t built to show that people felt healthier.
Another study followed 80 middle-aged adults. They took 300, 600, or 900 milligrams a day for 60 days.
Blood NAD+ and walking distance rose. Scores for daily life also rose against the placebo.
The paper called 600 milligrams a day the best tested amount. No safety problem appeared during the study [12].
A third trial included 25 women past menopause. Their blood sugar was nearing diabetes.
They used 250 milligrams a day for 10 weeks. Their muscles handled insulin better.
Weight and the long-term blood-sugar test didn’t change [13]. The gain was narrow, not a cure.
A 2021 review asked why NAD+ falls. It described several proteins that use the same supply [14].
Those proteins all draw from NAD+. The review didn’t prove that replacing NAD+ slows aging.
A 2025 study used heart tissue from people and mice. Both had one kind of heart failure.
NAD+ helped the heart cells burn fat again. That change depended on one protein [17].
The 2025 paper found better fat use. The broad 2025 review found one firm point [11].
Other gains varied by body part and group. Mice may live longer, but people haven’t proved that.
For you, a blood change isn’t a health gain. A study must test each claim on its own.
You can take the blood result seriously. Don’t stretch it into a promise about your health.
What NAD+ hasn’t proved and what may go wrong
Most people did well in short studies. Those studies can’t answer what happens after years.
Plain NAD+ pills may not raise cell levels much. Your gut doesn’t take in the whole compound well.
Two other pill forms enter the body another way. Your cells can then use them to make NAD+.
Sales claims often blur that difference. A label can’t prove the pill reached your cells.
NAD+ given through a vein leaves the blood fast. A fast drip can cause chest tightness.
People have also had cramps, flushing, and nausea. Clinics have reported those problems.
A pharmacy-made NAD+ shot carried germs or toxins. The federal drug agency issued its most serious kind of recall.
Cancer brings a harder question. Growing cancer cells also use NAD+.
More NAD+ might help an existing tumor grow. NAD+ also helps healthy cells repair DNA.
Both facts can be true. Human trials haven’t settled the risk over many years.
Federal officials have questioned whether one building form may be sold as a supplement. Rules in the US may still change.
The sources had no stories from people using NAD+ on their own. These warnings come from studies, not from a controlled trial [11][14].
Short tests can’t give you a long safety answer. Your own risks need care from a doctor.
How NAD+ differs from the other three compounds
NAD+ works inside each of your cells. That differs from raising growth hormone at the gland.
Ipamorelin and CJC-1295 act on that gland. NAD+ helps move energy and repair DNA.
Those ideas don’t cancel each other. They also haven’t been proved as one treatment.
NAD+ has the most human trials here. Even so, each gain applied to one set of people.
The 2025 review separates firm blood findings from unsure health gains. Keep that difference in mind.
You can set all four beside each other. Use the four-compound guide for that.
Your hopes can’t rank the compounds. Start with what a human test found.