NAD+ (nicotinamide adenine dinucleotide) is a coenzyme in every cell. It is not a peptide, but it is sold by the same telehealth services, and the nasal spray has become its convenience format: no needle, no drip chair, and a promise that the nose is a shortcut to the brain. This page sets out what has been measured when NAD+ is given through the nose.
Which peptide nasal sprays are approved, and why the nose only half works as a route, is on our peptide nasal spray page. What injected and infused NAD+ has shown in trials is set out in our record of NAD+ drip and injection claims, the drip against the capsule on our injection vs oral comparison, and the doses on our NAD+ dosage page. Nothing here is a recommendation.
The census
Two searches, both run on 20 October 2026 and both reproducible:
- PubMed: NAD, NADH, "nicotinamide adenine dinucleotide", nicotinamide riboside or NMN, together with intranasal, nasal spray or nose-to-brain, in title or abstract. 38 records. Most mention NAD+ only as a pathway measured in some other experiment (intranasal insulin, ketamine, testosterone, stem-cell extracts). Six gave NAD+ itself through the nose. None was in people.
- ClinicalTrials.gov: the terms "NAD+ intranasal", "nicotinamide adenine dinucleotide nasal", "NADH nasal", "NAD nasal spray" and "nicotinamide riboside intranasal", plus a sweep of 100 registrations with NAD as an intervention. One gives NAD+ as a nasal spray.
What the rodent studies found
| Study | Animal and model | Intranasal dose | Result |
|---|---|---|---|
| Ying et al. 2007, Front Biosci | Rat, transient focal brain ischaemia | 10 mg/kg, 2 h after | Brain NAD+ rose; infarct and deficits reduced; nicotinamide did not |
| Tsuchiyama et al. 2009, Neurol Res | Mouse, brain haemorrhage | 10 or 20 mg/kg | Brain NAD+ rose; injury not reduced |
| Won et al. 2012, J Neurotrauma | Rat, traumatic brain injury | 20 mg/kg | Fewer dying neurons at 7 days |
| Zheng et al. 2012, Neurosci Lett | Mouse, transient ischaemia | 50 mg/kg | Smaller infarcts; less autophagy |
| Zhou et al. 2015, Brain | Mouse, prion disease | Not stated in abstract | Activity improved in sick mice |
| Yoo et al. 2026, Exp Mol Med | Human olfactory stem cells in a dish; mice with zinc-induced loss of smell | Not stated in abstract | Smell function and olfactory lining recovered in mice |
Sources: PMIDs 17127275, 19298759, 22352983, 22260797, 25678560, 42380286, abstracts read 20 October 2026.
Three things carry over from this record and three do not. What carries: intranasal NAD+ reaches rodent brain tissue measurably; it protected brain cells in acute injury models; and one model, haemorrhage, showed no protection despite the NAD+ rise, so the effect is not automatic. What does not carry: the doses (10–50 mg/kg is 700–3,500 mg for a 70 kg adult by simple weight scaling, our arithmetic); the conditions (acute brain injury, not everyday focus); and the outcome (cell death and infarct size, not cognition in a healthy brain).
The one registered human trial
NCT07475546, "Combination Gerotherapeutic Interventions for Healthspan Improvement", read 20 October 2026:
- Sponsor: AgelessRx, a US telehealth company that sells NAD+ nasal spray.
- Size and status: estimated 30 participants; started 23 July 2025; active, not recruiting; no results posted.
- What the intervention groups receive: NAD+ nasal spray 30 mg a day, low-dose naltrexone, metformin and vitamin B12 in both intervention groups; the comprehensive group adds rapamycin, a weekly glutathione patch and a proprietary seven-compound supplement; app-guided meditation and a structured exercise programme. The control group takes vitamin C and vitamin E, listens to a podcast and follows a standard exercise regimen.
- Primary outcomes: VO₂ max, a commercial cognitive-test composite, an inflammation-age index and lean mass by DEXA.
Because the spray is never given alone, and never compared against a placebo spray, this trial cannot attribute any result to intranasal NAD+, whatever it finds. It is the closest the registry comes, and it is a test of a package.
What a seller's own page cites
The product page for AgelessRx's NAD+ nasal spray, read on 20 October 2026, priced it at $125 a month on subscription ($140 one-time) and made three claims worth reading against their footnotes:
- "Supports brain NAD+ levels through targeted intranasal delivery" — footnote 6, which the page describes as a preclinical study and dates Front Biosci, 2007: the rat stroke experiment in the first row of the table above.
- "Fast, convenient support for focus and mental clarity" — footnotes 1 and 5: a 2025 clinical study in Parkinson's disease using intravenous and intranasal NAD+ in HSOA Journal of Gerontology and Geriatric Medicine (not found in PubMed on 20 October 2026 and not opened here), and a review of nose-to-brain delivery as a strategy.
- "89% reported benefits by 2nd check-in" — explained on the page as self-reports from 131 surveyed customers between April 2022 and October 2025, all of whom had been approved for a prescription.
The page also states that the company is among the top ten teams in the XPRIZE Healthspan competition, studying NAD+ with other therapies; the registered trial above matches that description. Reading a seller's sources is not a verdict on the seller. It shows what the claim rests on: a rat study, a review, an unindexed paper, and a customer survey without a comparison group.
Who prescribes it, and what it is legally
Drugs@FDA (openFDA, searched 20 October 2026) lists no approved NAD+ product by any route; the sprays sold through telehealth are compounded or prepared by pharmacies to a prescription. FDA's findings on compounded NAD+ vials and the injected harms record are on our NAD+ injection side effects page. What the drip costs per milligram compared with the spray's monthly price is on our NAD+ price page.
What the record does not contain
- A published study of intranasal NAD+ in people, of any size.
- A measurement of human blood or brain NAD+ after a nasal dose.
- A trial comparing the spray with a placebo spray, or with injected or oral NAD+.
- A recorded side-effect rate for NAD+ nasal spray.
- An approved NAD+ product in the United States.
A plain explainer of the molecule is Peptide Lexicon's NAD+ entry. A prescriber who knows a person's medicines is the one to weigh any of this for an individual.
Sources and dates
Read 20 October 2026: PubMed query described above (38 records) and abstracts of PMIDs 17127275, 19298759, 22352983, 22260797, 25678560 and 42380286; ClinicalTrials.gov searches described above and record NCT07475546; AgelessRx NAD+ nasal spray product page (headless render), including its numbered references and survey footnote.