Blog · Wellness Shots
NAD side effects are one of the first things people ask about once NAD+ shots come up, and the honest answer has two parts: what small studies have reported, and how much nobody has measured yet. Below, Dr. Melanie Espinet, a board-certified family physician in Lutz, walks through NAD+ side effects by route, what an NAD+ shot feels like, and who should talk to a physician first. For the basics, start with what NAD is and what it does in your body.
Side effects depend a lot on how NAD+, or a building block of it, gets into your body. Here is what the published evidence shows for each route:
| How it is taken | Side effects reported |
|---|---|
| NAD+ by IV | Nausea, vomiting, stomach cramping, diarrhea, flushing, chest pressure or discomfort, and a faster heart rate, mostly during the infusion; clinicians also report sweating, headache, and feeling unwell |
| NAD+ as a shot | Not yet studied in published trials; like any shot, it can leave brief soreness or redness where the needle went in |
| Oral NR or NMN (NAD+ boosters) | Generally well tolerated in trials lasting weeks to months; mild stomach upset at higher NMN doses in one trial |
| NR plus pterostilbene | Raised total and LDL cholesterol at the higher dose in one trial |
| Niacin (nicotinic acid, vitamin B3) | Flushing: warmth, redness, itching, or tingling of the face, neck, arms, or upper chest |
The niacin row matters because people often mix it up with NAD+. Niacin is a form of vitamin B3 that your body can turn into NAD+, and its flush is well known. It is a different product from an NAD+ shot, though, and the nicotinamide form of B3 does not appear to cause that flush.
Here is the plain truth: we could not find a published study that measured the side effects of NAD+ given as a shot. A 2026 systematic review of NAD+ research found no outcome trials of NAD+ itself, given by IV or by injection, for anti-aging or wellness. Nearly all of the side effect data come from IV drips and oral supplements.
So what can you reasonably expect? Two things. The ordinary part: like any injection, an NAD+ shot can leave the spot a little sore or red for a short time, and a small bruise is possible, especially if you take a blood thinner. The borrowed part: flushing, nausea, and stomach discomfort are well described with IV NAD+, and anecdotal reports from wellness clinics tie them to how fast NAD+ goes in. Whether a shot causes them, and how often, has not been studied. If you feel warm, queasy, or unwell after an injection, say so right away.
NAD+ injection pain is usually brief. Like most shots, it feels like a quick pinch, and some people notice a short sting as the liquid goes in. Afterward, the spot may be a little sore or red for a short time. No study has measured how much NAD+ shots hurt compared with other shots, so ask what to expect when you book NAD+ injections in Lutz. A few things help the visit go smoothly:
Most of what is published about NAD side effects comes from IV studies. MeliOra does not offer IV drips, but these small studies are the best evidence anyone has, and they show a clear pattern:
| Small IV NAD+ study | Side effects seen |
|---|---|
| 8 people, 750 mg slowly over 6 hours | None observed during the infusion; small lab changes were judged not clinically significant |
| 8 adults aged 70 to 80, 1,000 mg a day for 6 days | Mild flushing and brief nausea; chest discomfort in some |
| 6 adults, 500 mg a day for 4 days (2026) | All six had moderate to severe cramping, nausea, vomiting, diarrhea, chest pressure, and a faster heart rate during infusions, which stopped once each infusion ended |
In that 2026 study, people controlled their own drip speed and slowed it down to cope, so NAD+ infusions averaged about 97 minutes. A comparison group given nicotinamide riboside the same way averaged about 37 minutes, and only some of those people had minor tingling or cramping. No adverse events were documented over the 30-day follow-up.
Why would fast NAD+ cause trouble? Researchers suspect that pushing NAD+ outside cells far above its normal level creates an inflammatory response. That fits with reports that rapid infusion brings on discomfort, flushing, or nausea, and that many clinics stretch drips to 2 to 4 hours. For how shots and drips compare on time, cost, and evidence, see NAD+ injections vs. IV drips.
Oral NAD+ boosters have the most safety data. They contain building blocks of NAD+ rather than NAD+ itself, because NAD+ is not absorbed directly from the gut. A 2023 review of human trials found nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) safe and well tolerated, with NR given at up to 2,000 mg a day and NMN studied for up to 24 weeks, and no signs of serious adverse effects. In one 28-day trial of NMN taken twice a day, mild stomach upset was reported at the higher dose. The exception worth knowing: when NR was paired with pterostilbene, the higher dose raised total and LDL cholesterol.
Niacin is a different story. Taken as a supplement, it can cause the classic flush described above, and too much niacin can raise blood sugar, damage the liver, or cause peptic ulcers and skin rashes. If you take niacin, NR, NMN, or any NAD+ supplement, tell your physician before adding a shot so your whole routine gets reviewed together.
For most healthy adults, the reactions reported so far are short-lived. But safe also means safe over months and years, and that has not been studied for any form of NAD+. A 2026 review of IV NAD+ concluded that long-term safety data are lacking and that the therapy should be considered investigational. Even for oral precursors, which have the most research, scientists say it is still unknown whether long-term use has side effects.
One open question involves cancer. In laboratory studies, NMN made aging (senescent) cells release more inflammatory signals and could promote inflammation-driven cancers, which led researchers to caution that long-term NAD+ boosting might carry downsides. That has not been shown in people, but it is why a cancer history calls for a careful conversation. The clinic in the 2026 IV study treated pregnancy and a family or recent history of cancer as reasons not to give IV NAD+. And because no NAD benefit for energy or aging has been proven yet, as our guide to NAD benefits and the evidence explains, the risk side of the scale deserves real weight.
If ongoing tiredness is what has you looking at NAD+, get the cause checked first. Low B12 is one common, testable reason, covered in our guide to B12 deficiency symptoms. An NAD+ shot is not a substitute for that workup.
After any injection, call 911 for chest pain, trouble breathing, or swelling of the face, lips, or throat. For nausea, flushing, or dizziness that does not pass, contact your physician the same day.
At MeliOra, NAD+ is a shot only. Before your first NAD Boost, Dr. Espinet reviews your health history, medications, and supplements, and if NAD+ is not a good fit for you, she will say so. She gives every shot herself, at your home or office anywhere in the Tampa Bay service area or at the Lutz office by appointment, with no travel fee. Each shot is $30, or 4 for $80, the same as the rest of the wellness shot menu.
She also sets honest expectations: NAD+ is optional nutrient support, not a treatment for any condition. To ask whether it makes sense for you, book a visit online or call or text (813) 726-5808, and read more about NAD+ therapy in Lutz and Tampa.
The side effects reported most often are nausea, stomach cramping, flushing, chest pressure, and a faster heart rate, mainly with NAD+ given by IV and mostly during the infusion. Oral NAD+ boosters such as NR and NMN have been well tolerated in short trials. NAD+ shots have not been studied in published trials yet.
The short-term reactions reported for NAD+ are usually brief, but NAD+ shots have not been tested in published clinical trials, and long-term safety is unknown for every form of NAD+. That is why a physician should review your health history, medications, and supplements before your first shot.
Usually only briefly: like most shots, an NAD+ injection feels like a quick pinch, and some people notice a short sting as it goes in. The spot may be a little sore or red for a short time afterward. Tell your clinician during the shot if anything feels off.
With IV NAD+, nausea seems to be tied to how fast NAD+ enters the bloodstream. Researchers suspect that raising NAD+ outside cells far above its normal level sets off an inflammatory response, and many clinics slow drips to 2 to 4 hours to reduce it.
In the published IV studies, side effects were brief and tied to the infusion itself. In one 2026 study, symptoms stopped as soon as each infusion ended, and no adverse events were documented in the 30 days that followed. How long reactions last after an NAD+ shot has not been studied, but mild soreness where any shot was given is usually short-lived.
Yes, flushing has been reported with IV NAD+, often along with nausea, and anecdotal clinic reports link it to fast infusion. Flushing is also the classic side effect of niacin supplements, a form of vitamin B3, which can cause warmth, redness, itching, or tingling of the face, neck, arms, or upper chest.
A faster heart rate was reported during IV NAD+ infusions in one small 2026 study, while blood pressure did not change significantly over the four days of treatment. The effect of NAD+ shots on heart rate has not been studied, so mention any heart condition before treatment.
People who are pregnant or breastfeeding should generally wait, since there is little safety data, and anyone with a current or past cancer should talk it through with a physician first. Kidney or liver disease, heart conditions, blood thinners, and other NAD+ supplements also need a review before a first shot.
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