NAD+ Injection: Subcutaneous and Intramuscular Protocols in the Research Literature
How injectable NAD+ compares to IV infusion and oral precursors — route pharmacokinetics, practitioner dose ranges, and the current evidence base.
What Is an NAD+ Injection?
An NAD+ injection is a subcutaneous (SC) or intramuscular (IM) administration of compounded NAD+ solution, delivering the molecule directly into tissue and bypassing the gastrointestinal degradation that limits oral NAD+ bioavailability. Unlike intravenous infusion, which requires clinical setup and rate-controlled delivery, SC and IM injections can be self-administered or clinic-administered in shorter sessions.
In the pharmacology hierarchy, injectable NAD+ sits between oral precursors (lowest plasma NAD+ elevation, slowest onset, most accessible) and intravenous infusion (highest plasma elevation, fastest onset, most clinical infrastructure required). The subcutaneous and intramuscular routes deliver NAD+ directly into interstitial fluid or muscle tissue, from which it is absorbed into systemic circulation over 15–60 minutes depending on the injection site and local blood flow.
As of 2026, SC and IM NAD+ injection protocols are active in registered clinical trials (including NCT06919328 and NCT07251608) but no completed, peer-reviewed RCT for these specific routes has been published. Practitioner protocols drawn from IV NAD+ clinical experience and oral precursor dose-ranging data are the current reference, pending those results.
Are NAD+ Injections Supported by Research?
The direct evidence base for SC/IM NAD+ injection is limited. What the adjacent literature establishes:
Oral NMN and NR RCTs confirm that raising the NAD+ pool produces measurable physiological effects — blood NAD+ elevation, muscle insulin sensitivity improvement, physical function gains — at dose ranges of 250–900 mg/day.[4][5][6][7] These studies establish proof of concept that NAD+ pool repletion has downstream effects, though they do not directly test injectable routes.
IV NAD+ case series and pilots show that injectable administration (intravenous) achieves plasma NAD+ elevations far exceeding oral dosing and produces functional outcomes in addiction and neurochemical settings.[9][11][12] SC/IM delivery bypasses the slow IV infusion requirement while still avoiding GI degradation.
Injectable NAD+ raises blood levels more rapidly than oral precursors — this is pharmacologically established from the IV PK study (Grant et al. 2019)[9] and from the underlying pharmacokinetics of subcutaneous drug delivery. Head-to-head comparison with oral NMN/NR protocols has not been completed in a published controlled trial as of 2026.
NAD+ Dosage in Research Protocols
NOTE
The following reflects the documented research record — not a dosing recommendation. All dose figures are from published peer-reviewed studies.
| Route / Formulation | Dose Range Studied | Key Trial / Reference | Primary Outcome |
|---|---|---|---|
| Oral NMN (single dose) | 100–500 mg | Irie et al. 2020[3] | Safe; dose-dependent metabolite rise |
| Oral NMN (daily, 12 wk) | 250 mg/day | Okabe et al. 2022[4] | Blood NAD+ elevated at wk 4, 8, 12 |
| Oral NMN (metabolic) | 250 mg/day × 10 wk | Yoshino et al. 2021[5] | Muscle insulin sensitivity improved |
| Oral NMN (dose-response) | 300–900 mg/day × 60 d | Yi et al. 2022[6] | 600 mg/day optimal; walking distance improved |
| Oral NMN (older men) | 250 mg/day × 12 wk | Igarashi et al. 2022[7] | Gait speed + grip strength improved |
| Oral NMN + exercise | 300–1200 mg/day × 6 wk | Liao et al. 2021[17] | VO₂max improved at 600 and 1200 mg/day |
| Oral NR (dose-response) | 100–1000 mg/day × 8 wk | Conze et al. 2019[8] | Blood NAD+ +22%, +51%, +142% |
| Oral NR (high-dose safety) | 3000 mg/day × 30 d | Berven et al. 2023[18] | No moderate/severe AEs; safe ceiling |
| IV NAD+ (PK) | 750 mg over 6 h (~2 mg/min) | Grant et al. 2019[9] | Plasma NAD+ elevated; PK profile established |
| SC/IM injection | 100–500 mg, 1–3×/wk | Practitioner protocols; NCT06919328 | Under active investigation — no published RCT |
Fig. 1 Abstract chrome dose-comparison composition — five dose cohorts of increasing magnitude; the highest (1200 mg/day) marked with iridescent glow.
NMN Dosage Studied in Adults Over 50
The Washington University RCT (Yoshino et al. 2021, Science) enrolled postmenopausal women with prediabetes and administered 250 mg/day oral NMN for 10 weeks. Skeletal muscle insulin-stimulated glucose disposal increased significantly vs placebo; no improvement in liver insulin sensitivity.[5]
The Igarashi et al. (2022, NPJ Aging) trial enrolled healthy older men at 250 mg/day for 12 weeks and showed significantly improved gait speed (p=0.033) and grip strength (p=0.019) in completers (n=20).[7]
The Yi et al. multicenter RCT enrolled middle-aged adults at 300, 600, or 900 mg/day for 60 days; the 600 mg/day arm showed the strongest combination of blood NAD+ elevation and physical function improvement.[6]
Injectable NAD+ protocols in adults over 50 are under active clinical investigation — no published SC/IM RCT in this population is available as of 2026. For the current IV protocol evidence, see NAD+ IV therapy.