NAD+ (nicotinamide adenine dinucleotide) is a coenzyme every cell uses to turn food into energy, and its levels fall with age in some tissues. That is the pitch behind NAD+ injections, IV drips, nasal sprays, capsules of its precursors NMN and NR — and adhesive patches worn on the skin. A patch is the easiest of these to sell and the hardest to justify from the record, for a reason that starts with the size of the molecule.
This page sets out that reason and the human record as a reproducible census. How NAD+ by injection compares with capsules is on our NAD+ injection vs oral page, the nasal route on our NAD+ nasal spray page, and the precursors on our NAD vs NMN page. Nothing here is a recommendation.
The size problem
Skin's outer layer, the stratum corneum, keeps most large molecules out. In 2000 two Amsterdam dermatologists, Bos and Meinardi, proposed that a compound must be under 500 daltons to be absorbed through intact skin, on three observations: virtually all common contact allergens are under 500 Da, the drugs used topically are under 500 Da, and every drug then used in a transdermal delivery system was under 500 Da (Bos & Meinardi 2000, Exp Dermatol). It is a rule of thumb, not a measured barrier for each molecule — charge, fat-solubility and the patch's formulation all matter too — but it is the yardstick dermatology uses.
| Molecule | Molecular weight (PubChem) | Against the 500 Da rule |
|---|---|---|
| NAD+ (nadide) | 663.4 Da | Above |
| NMN (nicotinamide mononucleotide) | 334.2 Da | Below |
| Nicotinamide riboside | 255.3 Da | Below |
| Glutathione | 307.3 Da | Below |
PubChem compound records 5892, 14180, 439924 and 124886, read 27 October 2026. NAD+ is also strongly charged, carrying two phosphate groups, which works against passive diffusion through the skin's fatty outer layer.
The precursors are smaller, which is the usual argument for precursor-based products. Being under 500 Da makes absorption possible, not proven; how the body handles each precursor once inside is on our NAD vs NMN page.
The human record, as a census
Run on 27 October 2026:
| Query | Records | Human NAD+ patch studies |
|---|---|---|
| PubMed: (NR OR NMN OR NAD+) AND (transdermal OR "skin patch"), title/abstract | 12 | 0 |
| PubMed: NAD AND (transdermal OR patch OR topical) AND "nicotinamide adenine dinucleotide", title/abstract | 40 | 0 |
| ClinicalTrials.gov: intervention "NAD", terms "transdermal OR patch" | 13 | 1 (no results) |
What the PubMed records are, where they touch the question at all: an ex vivo study delivering NMN through polymer microneedles (2023), 3D-printed microneedles for an NAD+ precursor (2024), a 2026 laboratory study of ion-coupled transfersome carriers "for enhanced transdermal NAD(+) repletion", and a 2026 mouse study on NAD+ deficiency in the skin itself. The research effort goes into piercing or carrying molecules across the barrier — a sign that plain passive absorption is the obstacle. None measures NAD+ in a person's blood after wearing a patch.
The one registered trial
ClinicalTrials.gov holds one human trial that gives NAD+ through a patch:
- NCT04604704 — "Pilot Study Into LDN and NAD+ for Treatment of Patients With Post-COVID-19 Syndrome", sponsored by AgelessRx, a telehealth longevity company. NAD+ was "applied using iontophoresis patches", with 400 mg of NAD+ solution on the positive electrode, alongside low-dose naltrexone 4.5 mg a day. Primary outcome: reduction of fatigue.
- Phase 2, 36 participants, started January 2021, completed 23 January 2023.
- No results posted on the registry, and no PubMed record cites its registry number (both checked 27 October 2026).
Two features limit what it could show even if published. Iontophoresis is not what most patches on sale are: it uses a battery-driven current to push charged molecules into skin, and is a device-assisted route. And with naltrexone in the same regimen, the NAD+ patch's own contribution would be hard to separate. Nearly four years after completion, there is no report to read.
Glutathione patches
Glutathione patches are sold on the same pitch and are often the second product in the same shop. Glutathione is under the 500 Da rule of thumb, so size is less of an obstacle — but the human record is no deeper. The one registered trial that uses one, NCT07475546 (also AgelessRx, estimated 30 participants, active), has one group wear "a topical patch for 4 hrs, once per week" alongside rapamycin, low-dose naltrexone, metformin, an NAD+ nasal spray, a proprietary seven-ingredient supplement, vitamin B12, structured exercise and guided meditation. A trial built that way can test a programme; it cannot tell anyone what the patch did. The same trial's NAD+ spray arm is described on our NAD+ nasal spray page. The glutathione nasal route has a small published record of its own, set out on our glutathione nasal spray page.
What a patch label can and cannot show
A patch's printed milligrams say how much NAD+ or precursor is in the adhesive. They do not say how much leaves it, how much crosses the skin, or how much reaches the blood — that needs a pharmacokinetic study, blood NAD+ measured before and after wear, and none has been published for a commercial patch. Our wider survey of peptide and supplement patches found the same gap for BPC-157 and other "peptide" patches: the topical studies used broken skin or creams, never an adhesive patch on intact skin.
NAD+ patches are sold as dietary supplements or cosmetics. Neither category requires FDA approval before sale, and neither has been reviewed by FDA for whether the product delivers what it claims.
What is not established
- Absorption of NAD+ through intact human skin from any commercial patch.
- Any change in blood or tissue NAD+ after wearing a patch.
- Any clinical benefit — energy, fatigue, cognition, ageing — from an NAD+ or glutathione patch.
- The result of the one completed human trial, finished January 2023 and unreported.
- Safety beyond the general risks of adhesive patches.
Anyone considering NAD+ products for a medical symptom, including post-COVID fatigue, should discuss it with a clinician; what has been studied by injection is on our NAD+ injection benefits page.
Sources and dates
- Bos JD, Meinardi MM. The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Exp Dermatol. 2000;9(3):165–9. PMID 10839713.
- PubChem compound records 5892 (nadide), 14180 (NMN), 439924 (nicotinamide riboside), 124886 (glutathione) — read 27 October 2026.
- PubMed E-utilities searches as printed in the census table, and record titles (PMIDs 37177177, 39312410, 42170234, 41665963) — 27 October 2026.
- ClinicalTrials.gov API v2: NCT04604704 and NCT07475546, and the intervention/term query — read 27 October 2026.