NAD+ injections and nasal spray: what the evidence says

In short: NAD+ is a molecule your cells use in many reactions. Precursor pills (NR, NMN) raise NAD+ levels in blood, but a 2026 systematic review in Ageing Research Reviews found no outcome trials of NAD+ injections, and nasal spray has animal data only. At Increase Health, a licensed provider decides whether compounded NAD+ suits you. Start with the peptide therapy questionnaire.

What is NAD+?

NAD+ (nicotinamide adenine dinucleotide) is a helper molecule, or coenzyme, that your cells use in many chemical reactions, including breaking down nutrients from food. Your body makes it, partly from forms of vitamin B3. Interest in taking extra NAD+ comes mostly from animal research. Human evidence is much thinner¹².

You may read that NAD+ falls as you age, so topping it up must help. The human data are less clear. A 2025 review found the age-related decline was consistent in only a limited number of human studies, and warned that results in rodents don't carry over to people in a straightforward way². A 2026 review noted that large human datasets suggest whole-blood NAD+ doesn't decline with healthy aging³.

Injection, nasal spray, IV or NR/NMN: what's the difference?

They're different products given different ways. NR and NMN are oral precursors your body turns into NAD+. Injections put NAD+ itself under the skin or into a muscle. IV drips put it into a vein over hours. Nasal spray goes into the nose. No trial has compared these routes on health outcomes, so none can be called best¹.

A higher level in your blood is not the same as a proven health benefit. That gap is the main reason the evidence is described as limited.

What do human studies of NAD+ injections show?

Very little so far. A 2026 systematic review of NAD+ research found no eligible outcome trials of NAD+ given by IV or intramuscular injection; most human data are on oral precursors. A separate 2026 review called the IV evidence "insufficient to support routine clinical or wellness use"¹³.

What the closest studies did and didn't show:

• An IV pilot study (2019). When NAD+ was infused into a vein, plasma NAD+ didn't rise for the first 2 hours. The body removed and broke down the infused NAD+ quickly. It was very small and measured no health outcomes, and some authors were linked to an NAD+ wellness business⁵.
• Precursor trials. In a small trial, 6 weeks of NR was well tolerated and raised NAD+ metabolism in healthy middle-aged and older adults; effects on the body were exploratory⁸. In another, NMN improved one measure of muscle insulin sensitivity in a narrow group of postmenopausal women with prediabetes⁹. These are different molecules taken by mouth. They don't tell us what injections do.
• Long-term safety. A 2020 review called long-term human trials "nascent" and raised theoretical risks that haven't been observed in people¹⁰.

We can't promise NAD+ will do anything for you. If you're interested, your care team and its licensed providers can talk it through with you, including whether it makes sense at all.

Is there evidence for NAD+ nasal spray?

We found no published human studies of NAD+ nasal spray. The only study we found looked at sense of smell in mice and at human smell-related stem cells grown in a dish⁷. The spray is needle-free, which some people prefer. Whether it works as well as, better than or worse than an injection is unknown.

If you're choosing between the two, the honest differences are practical: a spray versus a needle, and the price. Your care team can help you decide.

What side effects do people report?

The best-documented side effects come from IV drips: nausea and stomach upset, cramping, flushing, chest pressure or discomfort, and a faster heart rate during the infusion. In one clinic's records these eased when the infusion ended. Long-term safety isn't known, and data on injections and nasal spray are thinner still³⁶.

• People who use NAD+ injections often describe stinging or burning where they inject. That comes from user reports, not studies.
• There's no published side-effect data for NAD+ nasal spray. Tell your care team about anything unexpected.
• Your care team and its licensed providers will ask about your health first. On our intake, NAD+ isn't for people who are pregnant or breastfeeding, and people having treatment for cancer need clearance from their oncology team.

Is NAD+ FDA-approved?

No. The NAD+ we offer is compounded: a pharmacy prepares it for an individual prescription. Compounded medications are not FDA-approved, and FDA does not review them for safety, effectiveness or quality. NAD is in FDA's 503A "Category 1", which means it's under evaluation for compounding. That is not approval¹¹¹².

Category 1 means FDA doesn't intend to act against pharmacies compounding with NAD if certain conditions are met, while it decides whether NAD belongs on its final list¹³. Our guide to research peptides vs prescribed peptides explains the categories in more detail.

How do you get NAD+ through Increase Health, and what does it cost?

Complete the peptide therapy intake online. A licensed provider reviews it and prescribes NAD+ only if it's appropriate for you. The injection is $582 and the nasal spray is $510, each one payment for 3 months. Your card is charged only if a provider approves, and there's no subscription. Prices as of September 2026.

1. Complete the online intake.
2. A licensed provider reviews your health history.
3. If NAD+ is appropriate, you're prescribed it. If not, you pay $0.
4. You pay once for 3 months. Nothing auto-renews. Klarna's 4 interest-free payments are available.
5. Your medication ships to your door, and you can message your care team.

Compounded NAD+ is not FDA-approved, and FDA does not review it for safety, effectiveness or quality¹¹.

What people often get wrong

People often ask whether NAD+ boosts energy, slows aging or repairs cells. Here's each common claim next to what human studies have shown so far.