There is no FDA-approved NAD+ dose, by any route. Telehealth programs prescribe compounded subcutaneous NAD+ at doses set by the clinician, and IV clinics infuse hundreds of milligrams over hours. The only dose-ranging human trials are for the oral precursors NR and NMN, at roughly 250 to 2,000 mg a day.[3][6][7]
“How much NAD+ should I take?” has three different answers depending on the route, and only one of them is backed by trials that compared doses. This page sets out what each route has actually been studied at, explains why injection doses vary so much, and shows how to read a vial label. For whether NAD+ does anything at all, start with our NAD+ injections review and the NR and NMN evidence review.
Is there an approved NAD+ dose?
No. NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell. As a product, it is sold either as a dietary supplement precursor (NR or NMN) or as a compounded injection or infusion. No NAD+ product is FDA-approved for anti-aging, energy, recovery or addiction. Compounding pharmacies may prepare it while the FDA evaluates it: “Nicotinamide Adenine Dinucleotide (NAD)” sits in the FDA's 503A Category 1, the list of bulk substances under evaluation, as of the May 14, 2026 update.[9] Category 1 is a holding pattern, not an approval, and it comes with no dose.
| Route | Amounts studied or used | Quality of dose evidence |
|---|---|---|
| Oral NR (nicotinamide riboside) | 250 mg up to 1,000 mg twice daily | Randomized trials; dose-dependent rise in blood NAD+ |
| Oral NMN (nicotinamide mononucleotide) | 250 to 900 mg once daily | Randomized trials, including one dose-ranging trial |
| Subcutaneous injection | Set by the prescriber | No dose-finding study |
| IV infusion | About 500 mg to roughly 0.7 g per session in published reports | One pilot pharmacokinetic study; one retrospective tolerability review |
| Nasal spray | Set by the seller or prescriber | No dose-finding study |
What injection doses do telehealth providers prescribe?
Usually, a seller will not tell you before intake. The telehealth NAD+ pages we read for this article in October 2026 priced a monthly program and left the milligram dose to the clinician. One, Trellis Vitality, advertises injection plans from $129 a month without printing a dose. That is defensible practice, because there is no labeled dose to print. It also means two people on “NAD+ injections” may be taking very different amounts.
Why is there no standard? No trial has compared subcutaneous NAD+ doses in people, and a 2026 systematic review of 113 studies found no eligible outcome trials of IV or intramuscular NAD+ at all.[3] A prescriber choosing a dose is working from tolerability and experience, not from a dose-response curve. Before you start, ask three questions: how many milligrams per injection, how many injections per week, and what concentration the vial is. With those three numbers you can compare programs on our NAD+ therapy provider list, where partners are listed first.
How much NAD+ is in an IV drip, and why does it take hours?
The only human pharmacokinetic study of IV NAD+ infused it at 3 micromoles per minute for six hours. That works out to roughly 0.7 g. Plasma NAD+ and its breakdown products did not change for the first two hours. The authors concluded that infused NAD+ is “rapidly and completely removed from the plasma” at that rate. By six hours, NAD+ and a metabolite were showing up in urine.[1]
The slow drip is about tolerability. In a 2026 retrospective review from a commercial wellness chain, clients received 500 mg of NAD+ or of nicotinamide riboside by IV on four consecutive days. The NAD+ group reported moderate to severe stomach symptoms, a faster heart rate and chest pressure during the infusion. These symptoms stopped when the drip ended, but they slowed infusions to an average of 97 minutes, against 37 minutes for NR. Liver, kidney, inflammation and thyroid markers did not change. The authors worked for the chain that ran the infusions.[2] For more, see our NAD+ IV therapy review.
What doses did NR and NMN trials use?
These are the only NAD+ routes with randomized dose data, and the doses are well documented:[4][5][6][7][8]
| Trial | Compound and dose | Length | Main finding |
|---|---|---|---|
| Airhart 2017 (n = 8) | NR, 250 mg rising to 1,000 mg twice daily | 9 days | Blood NAD+ roughly doubled (p = 0.001); no adverse events |
| Martens 2018 (crossover RCT) | NR, 1,000 mg/day (500 mg twice daily) | 6 weeks per arm | Well tolerated; raised NAD+ metabolism |
| Dollerup 2018 (n = 40 RCT) | NR, 1,000 mg twice daily (2,000 mg/day) | 12 weeks | Safe; no improvement in insulin sensitivity |
| Yoshino 2021 (RCT) | NMN, 250 mg/day | 10 weeks | Improved muscle insulin sensitivity in women with prediabetes |
| Yi 2023 (n = 80 RCT) | NMN, 300, 600 or 900 mg/day | 60 days | Blood NAD+ rose at all doses (p ≤ 0.001), highest at 600 and 900 mg |
Two cautions. First, raising blood NAD+ is not the same as a health benefit. The 2026 systematic review found NR and NMN consistently raised NAD-related metabolites, but effects on function and metabolism were “heterogeneous and often null.”[3] At 2,000 mg a day for 12 weeks, NR did not improve insulin sensitivity in obese men.[6] Second, in the NMN dose-ranging trial, the benefit on blood NAD+ and walking distance plateaued at 600 mg; 900 mg added little.[7] One author worked for an NMN maker. See NMN vs NR for a head-to-head.
Can you compare an oral dose with an injected dose?
Not milligram for milligram. NR and NMN are precursors: the body converts them into NAD+, so 1,000 mg of NR is not 1,000 mg of NAD+. What the oral trials measured was the result. In the NR pharmacokinetic study, blood NAD+ roughly doubled at steady state.[4] Injected and infused NAD+ work differently. In the IV study, NAD+ was cleared from plasma so quickly that levels did not rise for the first two hours, and NAD+ and a breakdown product later appeared in urine.[1] No study has compared how much NAD+ reaches tissues after an injection versus an oral precursor. So a seller's claim that one route “absorbs better” than another is an argument, not a measured comparison of doses.
How often should NAD+ be dosed?
For oral precursors, the trials dosed daily, either once or split twice a day.[4][5][7] For injections and infusions, there is no trial-based answer. The commercial infusions in the 2026 review were given on four consecutive days.[2] Schedules like that come from commercial practice, not from studies comparing frequencies. The IV pharmacokinetic study suggests infused NAD+ is cleared from plasma quickly, which does not support any particular schedule.[1]
What side effects scale with dose?
With IV NAD+, the evidence says side effects scale with rate as much as with dose. In the 2026 review, 500 mg infusions brought stomach symptoms, a faster heart rate and chest pressure, which is why the drip was slowed.[2] Whether subcutaneous injections follow the same pattern has not been studied. Oral NR at up to 2,000 mg a day and NMN at up to 900 mg a day were well tolerated in the trials above, with no serious adverse events.[6][7]
How do I convert mg to mL or units on a NAD+ vial?
Divide the prescribed milligrams by the vial's concentration in mg per mL. That gives milliliters. On a U-100 insulin syringe, 1 mL equals 100 units, so multiply mL by 100 to get units. The table shows the arithmetic with example amounts. These are illustrations of the math, not dose recommendations. Always use the dose on your prescription and the concentration on your vial label.
| Example amount | At 100 mg/mL | At 200 mg/mL |
|---|---|---|
| 25 mg | 0.25 mL = 25 units | 0.125 mL = 12.5 units |
| 50 mg | 0.5 mL = 50 units | 0.25 mL = 25 units |
| 100 mg | 1.0 mL = 100 units | 0.5 mL = 50 units |
If your vial arrives as powder you mix yourself, the concentration depends on how much diluent you add. The reconstitution calculator handles that step, and the NAD+ format comparator lines up the routes on cost and evidence.
The bottom line
The only NAD+ doses tested in randomized trials are oral: about 1,000 to 2,000 mg a day of NR, or 250 to 900 mg a day of NMN. Both reliably raise blood NAD+, with mixed evidence of benefit beyond that.[3] Injection doses have no study behind them, and IV doses of 500 mg or more are limited by how fast the body tolerates them. If you choose an injection, get the milligram dose and the vial concentration in writing, and use them to compare.
