Does NAD+ nasal spray work? What the studies actually tested

Does NAD+ nasal spray work in humans?

Our November 2026 review found no controlled human trial demonstrating that NAD+ nasal spray improves energy, focus or other wellness outcomes. Animal studies and lab experiments give researchers leads to follow.

Who actually got the NAD+?

Open a 2026 paper on intranasal NAD+ and you'll find human-derived cells and living mice in the same study. That distinction changes the story. Researchers studied cellular responses in the lab and looked at smell-related behavior and tissue changes in mice with experimentally induced loss of smell. The human-derived cells tell you where some of the lab material came from. The mice tell you where the behavioral findings came from. Read the olfaction study.

An earlier experiment looked at brain injury in rats after researchers temporarily interrupted blood flow. It's a separate research question with a separate outcome. Read the rat study. Read what researchers know about brain exposure.

Where does a human case report fit?

One conference case described a person who received intranasal NAD with lidocaine by catheter and was also prescribed NAD+ lozenges. With one person, multiple interventions and no control group, the report can't isolate what caused the outcome. A commercial spray is a different intervention again. Read the conference case.

Put any claim through four questions

1. Compound. Was it NAD+ itself, or a precursor such as NR or NMN?
2. Route and formulation. Was it a spray, a catheter, a capsule or an infusion?
3. Study population. Were researchers working with cells, animals or people? If people, what was the comparison?
4. Outcome. Did they measure a lab marker, a symptom or a meaningful change in daily life?

Write the answers on one line. If the sentence you end up with differs from the claim you saw, you've found the missing step in the argument. Then see what a study would need to measure for energy or focus.