NAD+ Injections Before and After: What Studies Measured

PrescribedRX is a telehealth platform; prescriptions are written by licensed clinicians and filled by licensed partner pharmacies.

Short answer: No published trial has measured health outcomes before and after NAD+ injections. A 2026 systematic review of 33 human studies found “no eligible outcomes trials” of intravenous (IV) or intramuscular NAD+ for anti-aging or wellness (Gallagher and Emmanuel, 2026). The before-and-after measurements that do exist come from two small IV studies, one tracking NAD+ in plasma and urine during a single infusion and one recording symptoms, heart rate, blood pressure and blood tests in 6 clinic clients. We are not aware of any published human study of NAD+ injected under the skin.

This page lists what each cited study measured before and after, what changed, and what was never measured. It contains no photos or testimonials, because those are not measurements.

What does “before and after” mean for NAD+ injections?

Online, “before and after” for NAD+ usually means clinic stories and photos. A study can measure something specific instead: NAD+ in blood or urine, symptoms during treatment, vital signs, lab values, or a health outcome such as strength or blood sugar, ideally against a comparison group. NAD+ (nicotinamide adenine dinucleotide, listed in PubChem as nadide) is a coenzyme found in cells (PubChem); our explainer on whether NAD+ is a peptide covers the chemistry.

Below, each study is described by what it actually recorded at the start and at the end, using the authors’ own figures.

What have studies measured before and after IV NAD+?

Two human studies cited here gave NAD+ itself, both by IV drip.

Study	What was given	Who	Measured before and after	What was reported	Not measured
Grant 2019	IV NAD+ at 3 μmol per minute for 6 hours	Small pilot study	NAD+ and related metabolites in plasma and urine	No plasma change for the first 2 hours; NAD+ and methylnicotinamide found in urine at 6 hours	Health outcomes; NAD+ inside cells
Reyna 2026	500 mg IV NAD+ on 4 consecutive days (or 500 mg IV NR for comparison)	6 NAD+ clients and 8 NR clients at a commercial clinic, 30-day follow-up	Symptoms, blood pressure, heart rate, routine blood tests	All 6 NAD+ clients reported moderate to severe gastrointestinal symptoms, increased heart rate and chest pressure during infusions; metabolic findings “variable”	NAD+ levels; long-term outcomes

Grant 2019: a 6-hour infusion

In this pilot, NAD+ was infused at 3 μmol per minute for 6 hours, with blood and urine sampled along the way. Plasma NAD+ and its metabolites did not change until after 2 hours, and the authors wrote that NAD+ “is rapidly and completely removed from the plasma for at least the first 2 h.” NAD+ and methylnicotinamide were found in urine at 6 hours. The study measured blood and urine chemistry during one infusion, not how anyone felt or functioned afterward. The PubMed record lists NAD+ Research Inc. and Springfield Wellness Center among the author affiliations (Grant et al., 2019).

Reyna 2026: IV NAD+ vs IV NR at a commercial clinic

This retrospective review of medical records covered clients who received four consecutive days of 500 mg IV NAD+ (6 clients) or 500 mg IV nicotinamide riboside (8 clients), with 30 days of follow-up. All 6 NAD+ clients reported moderate to severe gastrointestinal symptoms, increased heart rate and chest pressure during infusions. NAD+ infusions averaged 97 minutes, compared with 37 minutes for NR. The authors reported that symptoms resolved when the infusion ended and called the metabolic findings “variable.” NAD+ levels were not among the reported outcomes. All authors were employed by Restore Hyperwellness, the commercial IV provider (Reyna et al., 2026).

If you are comparing clinic IV pricing, our NAD IV therapy cost page lists published prices.

What about NAD+ injected under the skin or into muscle?

We are not aware of any published human study measuring anything before and after a subcutaneous (under the skin) NAD+ injection. The 2026 systematic review, which searched studies published from January 2010 to October 2025, reported that “No eligible outcomes trials evaluated intravenous or intramuscular NAD⁺ itself for anti-aging or wellness indications.” It treated the IV pilot above as “contextual evidence only,” and concluded that clinical effectiveness “remains inconclusive,” calling for larger randomized trials, “particularly for parenteral approaches” (injections and IV) (Gallagher and Emmanuel, 2026).

Our page on what has been published about NAD+ injections goes through this record in more detail.

What do NAD+ precursor trials measure before and after?

Discussions of NAD+ injection results often cite trials of a different product: oral precursors, NR and NMN, which the body uses to make NAD+. These are different molecules taken by a different route, so their results do not show what an NAD+ injection does. They are listed here because they are the best-measured before-and-after data in the NAD+ field. Our NMN vs NAD+ comparison covers them in depth.

Study	What was given	Measured before and after	What was reported
Yoshino 2021	Oral NMN 250 mg/day vs placebo, 10 weeks, 25 women with prediabetes	NAD+ in blood cells and thigh muscle	Blood-cell NAD+ increased; muscle NAD+ did not change
Igarashi 2022	Oral NMN 250 mg/day vs placebo, 6 or 12 weeks, healthy older men	NAD+ in whole blood	NAD+ and its metabolites increased significantly
Martens 2018	Oral NR 500 mg twice daily vs placebo, two 6-week periods, 30 adults	NAD+ in blood cells	NAD+ about 60% higher than placebo

The 2026 review separated blood markers from health outcomes. It reported that oral NR and NMN “consistently demonstrated biochemical target engagement,” but described effects on functional, metabolic, vascular and other outcomes as “heterogeneous and often null or endpoint-specific” (Gallagher and Emmanuel, 2026). A 2025 meta-analysis in adults with a mean age over 60 reported that NMN had no significant effect on skeletal muscle index, grip strength, gait speed or chair-stand time (Prokopidis et al., 2025). For how oral products compare with injections overall, see NAD+ supplements vs injections.

Why can’t these studies predict an individual “after”?

The cited studies themselves set the limits:

• Small numbers. The IV NAD+ data cover one infusion pilot and 6 clinic clients (Grant 2019; Reyna 2026).
• No outcome trials. The 2026 review found no eligible outcome trials of IV or intramuscular NAD+ (Gallagher and Emmanuel, 2026).
• Commercial ties. Both IV studies list affiliations with companies or clinics that provide NAD+ therapy (Grant 2019; Reyna 2026).
• Different products. The precursor trials tested oral NR or NMN, not injected NAD+, and none of the studies on this page tested the compounded products listed below.

NAD+ offered through PrescribedRX

Two NAD+ products are offered through PrescribedRX, a subcutaneous injection and a nasal spray, both compounded. Compounded medications are prepared by licensed pharmacies and are not FDA-approved. The studies above did not test these products, so their results do not apply to them. Prices as displayed on the product pages in October 2026:

Product	Form as listed	3 month plan	Monthly plan
NAD+ Injection 200mg/mL 6ml (compounded)	Subcutaneous injection · Provider-dosed	3 month plan $412 · $137/mo · Billed every 3 months. Cancel anytime.	Monthly plan $169 a month
NAD+ Nasal Spray 200mg/mL 6ml (compounded)	Nasal spray · No needles	3 month plan $412 · $137/mo · Billed every 3 months. Cancel anytime.	Monthly plan $169 a month

A licensed provider decides whether it is appropriate for you, and your provider sets the dose. Plans are self-pay and availability varies by state. Every plan is listed on our pricing page.

When should you talk to a doctor?

Talk to a licensed provider before starting NAD+ in any form, especially if you have a health condition or take other medicines. The cited studies reported these reactions:

• IV NAD+: all 6 clients in one retrospective review reported moderate to severe gastrointestinal symptoms, increased heart rate and chest pressure during infusions (Reyna et al., 2026).
• Oral NR: 7 of 30 participants reported 14 mild adverse events, including nausea, flushing, leg cramps and increased bruising (Martens et al., 2018).

Our page on NAD+ side effects summarizes what has been reported for prescription NAD+. In an emergency, call 911.

Frequently asked questions

How long do NAD+ injections take to work?

No published trial has measured a timeline. The 2026 systematic review found no eligible outcome trials of IV or intramuscular NAD+, and we are not aware of any human study of subcutaneous NAD+. No published outcome trial supports a specific timeline.

What do NAD+ injections do in the body?

What has been measured is limited. In one 6-hour IV pilot, plasma NAD+ did not change for the first 2 hours and NAD+ appeared in urine by 6 hours. A 6-client clinic review recorded infusion symptoms and “variable” metabolic findings. Neither measured NAD+ inside cells or long-term health outcomes.

Are NAD+ injection before and after photos reliable?

Photos and testimonials are not controlled measurements, and none of the studies cited here used them. The before-and-after data that exist are blood and urine chemistry, symptoms, vital signs and lab values from two small IV studies.

See whether NAD+ is available to you

If you want a licensed provider to review whether NAD+ injection or nasal spray is appropriate for you, start with the eligibility check. Both are compounded, and the price is shown before you pay: “3 month plan $412 · $137/mo · Billed every 3 months. Cancel anytime.” You can also browse all longevity treatments.

Sources

1. Gallagher C, Emmanuel OO. NAD+ supplementation for anti-aging and wellness: a PRISMA-guided systematic review of preclinical and clinical evidence. Ageing Res Rev. 2026;116:103057. PubMed. Accessed Oct 2026.
2. Grant R, et al. A pilot study investigating changes in the human plasma and urine NAD+ metabolome during a 6 hour intravenous infusion of NAD. Front Aging Neurosci. 2019;11:257. PubMed. Accessed Oct 2026.
3. Reyna K, et al. Intravenous infusion of nicotinamide adenine dinucleotide (NAD+) versus nicotinamide riboside (NR): a retrospective tolerability pilot study in a real-world setting. Front Aging. 2026;7. Frontiers. Accessed Oct 2026.
4. Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372:1224-1229. PubMed. Accessed Oct 2026.
5. Igarashi M, et al. Chronic nicotinamide mononucleotide supplementation elevates blood nicotinamide adenine dinucleotide levels and alters muscle function in healthy older men. NPJ Aging. 2022;8:5. PubMed. Accessed Oct 2026.
6. Martens CR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun. 2018;9:1286. PubMed. Accessed Oct 2026.
7. Prokopidis K, et al. The effect of nicotinamide mononucleotide and riboside on skeletal muscle mass and function: a systematic review and meta-analysis. J Cachexia Sarcopenia Muscle. 2025;16(3):e13799. PubMed. Accessed Oct 2026.
8. National Library of Medicine. PubChem Compound Summary: Nadide (NAD+), CID 5892. PubChem. Accessed Oct 2026.

This article is for general information. It is not medical advice and it is not a recommendation for any particular treatment. Whether a treatment is appropriate for you is a decision for a licensed clinician who has reviewed your health history and current medications.