Here's the short version. Tirzepatide is a well-studied, approved drug. NAD+ injections are not. The cited evidence does not establish the combination’s benefit or safety. Lack of a documented interaction is not reassurance.
Is it safe to take them together?
The cited literature does not characterize a direct interaction or establish the combination’s safety. Missing interaction data should not be read as reassurance. Mechanistic work on NAD+ pathways does not establish the clinical effect of administering NAD+ alongside tirzepatide.
That puts the decision with your prescriber. Tell them about every injection, pill and supplement you take, including NAD+ from a clinic or spa. Diabetes medicines matter most, because tirzepatide lowers blood sugar on its own.
There's a practical snag too. Tirzepatide's most common side effects are stomach-related: in its weight-loss trials, nausea affected 25% to 29% of people on it versus 8% on placebo [7]. NAD+ injections have no FDA label, so there's no FDA-reviewed list of their side effects. Start both at once and it's hard to tell which one is behind a new symptom.
What each one does
Tirzepatide is a weekly injection that acts on two gut-hormone receptors, GIP and GLP-1. It lowers appetite and blood sugar. NAD+ is a coenzyme every cell uses to make energy. Clinics give it as an injection or IV drip, but its effects in healthy people are unproven.
| Tirzepatide | NAD+ injection | |
|---|---|---|
| FDA status | Approved: Zepbound (weight management, sleep apnea) [7], Mounjaro (type 2 diabetes) [8] | Not approved; Category 1 is conditional interim policy [6] |
| Human outcome evidence | Large trials: 15% to 21% average weight loss at 72 weeks in SURMOUNT-1 [2] | No eligible IV/IM wellness-outcome trials in the review's search through October 2025 [5]; one heart-failure trial [4] |
| Combination benefit | Not established in cited studies | Not established in cited studies |
| Interaction profile | Not established for this pair | Not established for this pair |
Zepbound is labeled for long-term weight reduction in adults with obesity, or overweight with a weight-related condition, and for moderate to severe obstructive sleep apnea in adults with obesity [7]. Mounjaro is labeled for type 2 diabetes and for lowering the risk of major heart events in adults with type 2 diabetes at high risk [8].
What NAD+ injections have actually shown
Human studies of injected NAD+ have measured blood levels and, in one heart-failure trial, heart pumping strength. The cited studies do not establish weight-loss benefit.
- A 6-hour IV pilot study found NAD+ left the blood so fast that plasma levels didn't rise for the first two hours [3]. Its authors included people tied to an NAD+ clinic.
- A heart-failure trial of 180 adults gave IV NAD+ or placebo for 7 days on top of standard care. Ejection fraction, a measure of pumping strength, was slightly higher at one month (45.4% vs 42.4%). The difference in heart events at six months wasn't statistically significant [4].
- A 2026 systematic review of 33 human studies found no eligible IV/IM NAD+ outcome trials for anti-aging or wellness in its search through October 2025 [5]. Its first author owns a business serving an aesthetics clinic, which the paper says does not offer NAD+. A separate 2026 retrospective clinic study compared IV NAD+ with IV NR; its observational design does not establish a wellness benefit or a tirzepatide interaction [1].
How long people expect NAD+ to take, and what they report, is in how long NAD+ injections take to work. Shots versus drips are compared in NAD+ injections or IV.
Does NAD+ boost weight loss on tirzepatide? No trial shows it
The cited studies do not establish that benefit. A claim that NAD+ enhances GLP-1 results needs direct clinical evidence.
Tirzepatide's weight-loss results come from its own large trials. In SURMOUNT-1, people lost 15% to 21% of their body weight on average over 72 weeks, against 3% on placebo [2]. Those trials do not establish what adding NAD+ would change. If you want help keeping muscle while the weight comes off, the evidence points to training and protein, covered in building muscle on tirzepatide.
NAD+ shots vs NAD+ precursor pills
NMN, NR and nicotinamide are oral precursors. Your body turns them into NAD+, and each has its own small set of trials. They aren't the same as NAD+ injections, and studies of one don't tell you about the other.
If you take a precursor pill, mention it to your prescriber the same way you would a shot. Pairing NMN with NAD+ is covered in NMN and NAD+ together.
What to ask your prescriber
If you're thinking about adding NAD+, these five questions cover what matters:
- What do you expect NAD+ to add, given that the cited studies do not establish this combination?
- Does anything else I take, especially diabetes medicine, change how careful we need to be?
- Should I start one at a time, so we can tell which one causes a side effect?
- Which licensed pharmacy compounds the NAD+, and in what form?
- How will we decide whether it's helping, and when would we stop?
A good prescriber will have a straight answer to each. If the answer to the first one is "it boosts your results", ask for the study.
One prescriber, one list
A program may offer NAD+ and tirzepatide, but that does not guarantee one clinician oversees both. Ask who reviews the complete medicine list. That makes it easier to sort out side effects and keeps your medicine list in one place.
Getting both from separate places works too. Just bring the full list to each. Where to start, and what NAD+ costs, are in where to get NAD+ injections and NAD+ injection cost.
If you're also weighing sermorelin with tirzepatide, that pairing has its own page: sermorelin and tirzepatide together. For the bigger picture by goal, see the metabolic health shortlist or the energy shortlist.