What NAD+ is, and why people take it
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme in every cell. With its partner NADH, it carries electrons in the reactions that make ATP, the cell’s energy currency, and it is consumed by signaling enzymes such as the sirtuins and PARPs.
Interest in NAD+ comes from studies of aging. NAD+ fell with age in human skin samples, and brain scans show age-related reductions. Blood is less clear: one study found plasma NAD+ declining with age, while a 2022 study of 1,518 adults found no age difference in women, and a 2026 study across seven cohorts in Nature Metabolism found whole-blood NAD+ “remarkably stable with age.”
The best-studied way to raise NAD+ is a pill. In randomized trials, nicotinamide riboside (NR) at 100, 300 and 1,000 mg a day raised whole-blood NAD+ by 22%, 51% and 142% within 2 weeks, and nicotinamide mononucleotide (NMN) raised blood NAD the most at 600 and 900 mg a day. In published human studies, NAD+ itself has been given only as an IV infusion.
What the evidence on nasal NAD+ shows
In people. Searches of PubMed, Europe PMC and ClinicalTrials.gov on October 3, 2026 found no published human study of NAD+ given through the nose. One trial is registered: a 90-day pilot sponsored by AgelessRx, with about 30 participants, that uses a 30 mg-a-day NAD+ spray only in combination with low-dose naltrexone, vitamin B12, metformin and other agents. No group takes the spray on its own, and no results have been posted.
In animals. Five rodent studies have given NAD+ through the nose, all in models of acute injury or disease:
- Rat stroke (2007). 10 mg per kg, given 2 hours after the stroke, raised brain NAD+ and sharply reduced brain damage at 24 and 72 hours.
- Rat brain injury (2012). 20 mg per kg given right after injury protected neurons in the hippocampus and reduced microglial activation at 7 days. Cortical neurons were not protected.
- Mouse prion disease (2015). Improved activity and delayed motor decline.
- Mouse loss of smell (2026). 100 mg per kg a day for 4 weeks improved smell and repaired the olfactory lining.
- Mouse brain bleed (2009). Brain NAD+ rose, and brain injury at 24 hours was unchanged.
Those results do not transfer to people directly. The olfactory area, the part of the nose that connects most directly to the brain, makes up as much as 50% of the nasal lining in rodents and about 10% in humans, and a 2026 review describes human evidence for nose-to-brain delivery as limited.
What absorption depends on. NAD+ is a large, very water-loving molecule (molecular weight 663). Molecules like that cross the nasal lining mainly through the gaps between cells, which tight junctions restrict. The nose also clears what is sprayed into it, with a half-life of about 21 minutes, and each nostril holds only 100 to 150 microliters. No study has measured how much NAD+ reaches the blood from a spray in people.
So when you see claims of “40 to 60% bioavailability,” NAD+ that “enters circulation within minutes,” or NAD+ that “drops 50% with age,” know that no human study backs any of them.
Nasal spray vs injection vs IV
| Nasal spray | Injection under the skin | IV infusion | |
|---|---|---|---|
| How it is used | 1 to 2 sprays per nostril, once a day | A small injection, daily or every other day | In a clinic, over one to several hours |
| Human data on NAD+ itself | None published; one combination trial registered | None published; one trial registered, measuring injection pain | A 2019 pilot and two later studies (details below) |
| Needles | None | Yes, small | An IV line |
| Reported side effects | Sellers describe nasal irritation and headache; no clinical data | No published data | Nausea, cramping, chest pressure and a faster heart rate in a 2026 clinic review |
The IV research is the only human data on NAD+ itself. In the 2019 pilot, 750 mg infused over 6 hours caused no adverse events, and plasma NAD+ did not change for the first 2 hours. In a 2024 randomized study, posted as a preprint, 500 mg of IV NAD+ caused more and more severe infusion reactions than IV nicotinamide riboside, and a 2026 review of clinic records found that all six people given 500 mg of IV NAD+ had moderate to severe stomach symptoms, chest pressure and a raised heart rate. A 2026 systematic review of 113 studies found no outcome trial of IV or intramuscular NAD+ for anti-aging or wellness.
The choice between a spray and an injection comes down to routine and comfort, because neither route has human absorption data to compare. For dosing by route and the units math, see NAD+ dosage; for injections, NAD+ injections explained.
Side effects
No clinical study has recorded side effects of NAD+ nasal spray in people. Sellers describe nasal irritation, sneezing, runny nose, headache, fatigue and stomach discomfort, usually as mild. The stronger effects reported with IV NAD+, such as cramping and chest pressure, were seen with infusions that push blood NAD+ well above normal levels, and no study has looked for them with a nasal spray.
The pharmacy behind a spray matters. In 2024, FDA warned compounders against using food-grade NAD+ after reports of chills, shaking and vomiting from NAD+ injectables, reactions consistent with bacterial endotoxin, and a 2026 FDA warning letter described an unopened NAD+ vial with 3,360 endotoxin units per mL from a lot that three patients had reacted to.
Storage
NAD+ is fragile. FDA has noted that it “degrades substantially when exposed to light, moisture, alkaline pH, or standard room temperatures,” and at least one 503A pharmacy labels its NAD+ nasal spray for the refrigerator at 36 to 46°F. Store your spray as your pharmacy label directs.
Is NAD+ nasal spray legal?
A prescription NAD+ nasal spray is compounded by a licensed pharmacy for one patient, and it is not FDA-approved. FDA lists NAD in Category 1 of its 503A bulk drug substances, “under evaluation” for the bulks list, as of its May 14, 2026 update. Under its interim policy, FDA has said it does not intend to take action against 503A pharmacies compounding a Category 1 substance while it is under review, unless significant safety issues arise.
Some sellers offer NAD+ sprays without a prescription, as supplements or labeled “Research Use Only.” FDA’s position is that a nasal product cannot be a dietary supplement, because a supplement must be intended for ingestion. A prescription spray comes from a licensed 503A pharmacy, with a clinician who has reviewed your history.
What NAD+ nasal spray costs
These are ongoing prices from each provider’s own page, read October 3, 2026. Where a membership or visit fee is required, it is part of the real cost.
| Provider | Ongoing price | Membership or visit fees | Strength and amount stated |
|---|---|---|---|
| AgelessRx | $125/mo on subscription ($140 one-time) | None stated | 300 mg/mL, a 14 mL bottle a month |
| Wisp | $150/mo on subscription ($175 one-time) | None shown | 300 mg/mL, 15 mL a month |
| MyFastRx | $139 for one month; $99/mo on a 3-month plan ($297) | None shown | Not stated |
| Midi Health | $165 per 30-day supply | Self-pay visits: $250 first, $150 returning | 15 mL |
| Eden | $112 first month; later price not shown | Required: $39 first month, then $99/mo | Not stated |
| PepScribe | $149/mo on the 3-month plan ($447 every 3 months); $159 month to month | None | 300 mg/mL, 15 mL |
When you compare, line up the concentration and the bottle size, and add any required membership or visit fees to the monthly price.
How to get NAD+ nasal spray through PepScribe
- Start the free online visit at /book/nad-plus and answer questions about your health and the medicines you take.
- A licensed clinician reviews your answers and decides with you whether NAD+ fits, and whether the nasal spray or the injection suits your routine.
- If NAD+ is prescribed, your spray is compounded in the USA by a licensed 503A pharmacy and shipped to you.
Plan details are on the NAD+ nasal spray page.
Frequently asked questions
Does NAD+ nasal spray work?
No published study has tested it in people. In rodents, NAD+ given through the nose raised brain NAD+ and protected the brain in some injury models, though not in all of them. Oral NR and NMN are the forms with human trials showing higher blood NAD+.
Is NAD+ nasal spray better than injections?
Neither route has human data on how much NAD+ reaches the blood, so the choice comes down to routine. The spray needs no needles; injections are given under the skin daily or every other day.
How do you use NAD+ nasal spray?
Follow your pharmacy label. PepScribe’s pharmacy directs 1 to 2 sprays per nostril once a day from a 300 mg/mL bottle.
What are the side effects of NAD+ nasal spray?
No clinical study has recorded them. Sellers describe nasal irritation, sneezing, runny nose, headache, fatigue and stomach discomfort, usually as mild.
Does NAD+ nasal spray need to be refrigerated?
Store it as your label directs. FDA notes that NAD+ breaks down with light, moisture and room temperature, and at least one 503A pharmacy labels its spray for the refrigerator.
Can you buy NAD+ nasal spray without a prescription?
Some sellers offer it as a supplement or for “research use only.” FDA’s position is that a nasal product cannot be a dietary supplement, because a supplement must be intended for ingestion.
How much does NAD+ nasal spray cost?
Among the US sellers we checked on October 3, 2026, ongoing prices ran from $99 to $165 a month. At PepScribe, NAD+ nasal spray plans start from $99/mo.
Provider prices: each provider’s own page, read October 3, 2026 (AgelessRx, Wisp, MyFastRx, Midi Health, Eden). PepScribe’s prices: its plan catalog, the same day. Prices change; check before you compare.
