Persistent tiredness usually is not one problem. Five of them are measurable: NAD+ falls with age, cells cannot make energy without it, recovery slows, the brain draws on the same supply, and caffeine borrows energy rather than making it.
Longevity
Published by Astra, which offers some of the treatments discussed. Educational, not medical advice.
NAD+ is not a supplement fad in the way that word is usually meant. It is a coenzyme that every cell in your body needs to run its energy metabolism, and its decline with age has been measured directly in people, not inferred from mice. An analysis of the human plasma NAD+ metabolome across adult ages found that it is dysregulated in what the authors called 'normal' aging: the balance of NAD+ and its related metabolites shifts as people get older 1.
Tissue tells a similar story. A study of human tissue samples across the lifespan found age-associated changes in NAD+ metabolism, arriving alongside markers of oxidative stress, with older tissue carrying less of the coenzyme than younger tissue 2.
Two honest caveats belong here. First, this is a population pattern, not a personal diagnosis: there is no routine clinical test that tells you your NAD+ level and no threshold that defines being low. Second, a decline in a coenzyme is a plausible contributor to feeling flat, not a proven cause of your particular tiredness. Anemia, thyroid disease, sleep apnea, depression, medication side effects, and simple sleep debt are all more common explanations, and all of them are worth ruling out with a clinician first.
This is the mechanism that makes reason one matter. NAD+ is the electron carrier that the energy-producing reactions of metabolism hand their electrons to. Glycolysis, the citric acid cycle, and oxidative phosphorylation all depend on the constant cycling of NAD+ to NADH and back again. A comprehensive review of NAD+ metabolism during aging lays out that dependency in detail, along with the reason a shrinking pool matters beyond fuel burning: NAD+ is also the required substrate for the sirtuin and PARP enzyme families that handle DNA repair and metabolic signalling, so those enzymes and the energy pathways all compete for the same supply 3.
Put simply, your cells cannot make ATP from food without NAD+ in the loop. That is not a marketing claim, it is textbook biochemistry, and it is the reason NAD+ ended up at the centre of the tiredness conversation in the first place.
What the mechanism does not tell you is how much a given person's fatigue is explained by it. Mechanism explains why something could work. Trials tell you whether it does. The next reason is where those two meet.
Being tired is often less about the energy you can produce on a good day and more about how long it takes to come back from an ordinary one. A randomized, placebo-controlled trial gave an oral NAD+ precursor to older adults for 12 weeks and reported improvement in fatigue measures in the treated group compared with placebo 4. That is the single most relevant human finding in this article, so it deserves its limits stated in the same breath: it is a small trial, in older adults specifically, using an oral precursor rather than an injection, over a defined 12-week window, with self-reported fatigue as the outcome.
A separate randomized crossover trial in older individuals looked at the recovery side more directly. Acute supplementation with an NAD+ precursor improved measures of redox homeostasis and exercise performance in old participants, while the same protocol did not produce the same effect in young participants 6. The age split is the interesting part, and it is consistent with the idea that topping up a supply matters most in the people whose supply has fallen.
Neither trial says that raising NAD+ will make you feel young. Together they say something more modest and more useful: in older adults, in controlled conditions, precursor supplementation has produced measurable improvements in fatigue and in recovery-related performance. That is a real signal in a field with a lot of noise.
Most people who describe themselves as always tired are not describing sore legs. They are describing a mind that will not start: slow recall, a short attention span, an afternoon where reading the same paragraph three times is normal. The brain is metabolically expensive, and it depends on the same NAD+ pool as everything else.
A 2022 review examined supplementation with NAD+ and its precursors in the context of brain function and cognitive performance, summarising the mechanistic case and the state of the human evidence in that area 5. The mechanistic case is strong. The clinical case is not settled, and the review is a review, not a trial.
The practical takeaway is a framing one. If your tiredness is mostly cognitive, that does not mean it is imagined or purely psychological. It means the tissue with the highest metabolic demand in your body is the first place a constrained energy supply shows up.
Caffeine is a genuinely useful drug and this is not an argument against it. It is an argument about what it does. Caffeine works by blocking adenosine receptors, which is to say it interferes with the signal that tells your brain you are tired. It does not add a single unit of energy to your cells. The only thing that does that is metabolism converting fuel into ATP, and that process runs on NAD+ 3.
This is why the fourth coffee of the day stops helping. You are not short on adenosine blockade at that point, you are short on the thing the blockade was hiding. Caffeine borrows against tiredness and the loan comes due, usually as an afternoon crash or as a night of worse sleep that makes the following day harder.
The useful mental model: caffeine changes the perception of fatigue, sleep repays the debt, and cellular energy production is what sets the ceiling on how much you have to spend in the first place. All three are separate levers, and only the first one comes in a cup.
The version of NAD+ most people have heard of is the clinic drip: several hours in a chair, an infusion line, and a bill to match. That is not the only delivery route, and for most people it is not the practical one.
Astra offers compounded NAD+ injection as an at-home, physician-prescribed option. It is a small subcutaneous injection you administer yourself on a schedule your clinician sets, dispensed by a state-licensed US compounding pharmacy after a licensed physician reviews your intake. No appointment, no infusion chair, no clinic afternoon.
Two things must be said plainly, because they are true and because this page is an advertisement as much as it is an explainer. Compounded NAD+ injection is not FDA-approved. And the human evidence discussed above is largely evidence for oral precursors, not for injected NAD+, whose direct human literature remains thin. If you try it, try it knowing that.
Rule out the common causes first. Persistent tiredness is a symptom with a long differential, and the cheap, boring answers are the likeliest ones: insufficient or fragmented sleep, iron deficiency, thyroid dysfunction, sleep apnea, depression, alcohol, and medication side effects. A basic workup with a clinician is a better first purchase than any supplement.
Then fix the inputs that have the strongest evidence behind them: consistent sleep timing, regular aerobic and resistance exercise, adequate protein, and daylight early in the day. None of these are exciting and all of them outperform anything in this article.
Consider NAD+ support last, not first, and consider it as an experiment with a defined window rather than a permanent purchase. The trials that found something found it over 12 weeks in older adults 46. If you are going to try it, give it that long, then judge honestly whether anything changed.
Caffeine changes how tired you feel. Sleep repays what you owe. Only metabolism makes new energy, and metabolism runs on NAD+.
Astra Editorial
Nobody can promise that, and anyone who does is selling past their evidence. A 12-week randomized trial of an oral precursor in older adults reported improvement in fatigue measures against placebo, and an acute trial found performance and redox benefits in older but not younger participants 46. That is a signal in specific populations, not a guarantee for any individual.
Not on the published evidence. Most of the human trial data is for oral precursors such as nicotinamide riboside and nicotinamide mononucleotide, not for injected NAD+. Injection avoids first-pass metabolism, which is a mechanistic argument rather than a demonstrated clinical advantage.
No. Astra's program is an at-home subcutaneous injection prescribed by a licensed physician and dispensed by a state-licensed US compounding pharmacy, so there is no clinic infusion appointment involved.
There is no reason to, unless it is disrupting your sleep. Just be clear about what it does: caffeine blocks the adenosine signal that reports tiredness, it does not increase the amount of energy your cells can produce 3.
Astra's compounded NAD+ injection is prescribed and supervised by a licensed physician and dispensed by a state-licensed US compounding pharmacy. It is not FDA-approved, and the injectable-specific human evidence is thinner than the oral precursor evidence described above. Rule out the common causes of fatigue with a clinician first, then decide.
This guide is educational and is not medical advice. Compounded medications are not FDA-approved. Speak with a licensed physician about your own care.