# NAD+ Injection Side Effects: What's Common and When to Call Your Provider **By TelosRX Editorial Team** ยท 2026-10-09 **The most commonly reported NAD+ injection side effects are mild: redness, soreness or swelling where the needle went in, plus flushing, nausea, headache, tiredness or lightheadedness. Most people describe them as short-lived. Anything severe, spreading or lasting should go to your provider, and signs of an allergic reaction need urgent care.** If you are weighing a NAD+ shot, side effects are a fair thing to ask about first. This guide covers NAD injection side effects specifically: what tends to show up at the injection site, what can happen body-wide, how that compares with IV drips and a nasal spray, and when to call for help. Looking for every route at once? Our general guide to [NAD+ side effects](https://www.telosrx.com/blogs/hormone-longevity/nad-side-effects) covers oral, IV and nasal use too. This page stays with injections. ## What NAD+ is, in one paragraph NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell. It shuttles between NAD+ and NADH in the reactions that turn food into usable energy, and enzymes involved in DNA repair use it too. It is not a peptide, a vitamin or a hormone. For the full background, start with our [NAD+ injection guide](https://www.telosrx.com/blogs/hormone-longevity/what-is-nad-injection-guide). One honest caveat up front: human research on subcutaneous and intramuscular NAD+ is limited. Most published human data come from IV studies or from oral precursors such as NR and NMN. So the reactions below are what is commonly reported with injections, not rates measured in large trials. ## Common NAD injection side effects Reported reactions fall into two groups: what happens at the spot you injected, and what you might feel more generally. ### At the injection site - **Stinging or burning** while the dose goes in. - **Redness** around the site. - **Soreness or tenderness** afterward. - **Mild swelling or a small lump** under the skin. - **Light bruising**, as with any needle. These are usually local and fade on their own. Rotating sites and a slow, steady push are the habits most often recommended to keep them down. Our step-by-step [subcutaneous injection walkthrough](https://www.telosrx.com/blogs/hormone-longevity/how-to-inject-nad-subcutaneous-guide) covers technique in detail. ### Body-wide reactions - **Flushing**, a warm or red feeling in the face, neck or chest. - **Nausea** or a queasy stomach. - **Headache.** - **Fatigue**, or feeling unusually tired after a dose. - **Lightheadedness** or feeling briefly dizzy. People describe these as passing rather than lasting. Still, they are worth logging. A note of the date, dose, site and how you felt gives your provider something real to work with if a change is needed. ## Why the route changes the experience A subcutaneous shot puts NAD+ into the fat layer just under the skin, usually on the abdomen or thigh, with a short, fine needle. An intramuscular shot goes into muscle, such as the deltoid or thigh, with a longer needle. Your prescriber and the pharmacy instructions decide the route. For more on the under-the-skin approach, see [NAD+ subcutaneous injection explained](https://www.telosrx.com/blogs/hormone-longevity/nad-subcutaneous-injection-explained). Different routes bring different kinds of discomfort. Here is how they compare in plain terms. Route Where discomfort tends to show up Human evidence **Subcutaneous injection** Injection site (sting, redness, soreness), plus possible flushing, nausea or headache Limited **Intramuscular injection** Deeper muscle soreness at the site, plus similar body-wide reactions Limited **IV infusion** The cannula site, and how you feel during a long, clinic-paced session Small pilot studies **Nasal spray** Nasal irritation, stinging or a runny nose; no needle Limited On IV specifically, the best-known human data point is a small 2019 pilot study. Eight people received NAD+ as a slow infusion over 6 hours, and the researchers reported no adverse events during that infusion ([Grant et al., Frontiers in Aging Neuroscience, 2019](https://pmc.ncbi.nlm.nih.gov/articles/PMC6751327/)). It was a small study of one slow rate, so it cannot tell you how faster drips or injections compare. Our [NAD+ injection vs IV therapy](https://www.telosrx.com/blogs/hormone-longevity/nad-injection-vs-iv-therapy) guide goes further. If needles are the sticking point, a nasal spray avoids injection-site reactions entirely, though it can irritate the nose. The [nasal spray vs injections comparison](https://www.telosrx.com/blogs/hormone-longevity/nad-nasal-spray-vs-injections) lays out the trade-offs. Not sure whether an injection or a needle-free spray suits you better? A licensed provider can help you choose, based on your history and how you feel about needles. [See if NAD+ is right for you](https://www.telosrx.com/pages/lp8nad) ## Who should be cautious with NAD+ injections NAD+ injections are not right for everyone. A provider will ask about your health before prescribing, and some situations call for extra care. - **Pregnancy or breastfeeding.** There are not enough safety data for NAD+ supplementation in pregnancy or while nursing. Read more in [NAD+ and pregnancy](https://www.telosrx.com/blogs/hormone-longevity/nad-and-pregnancy). - **A current or past cancer diagnosis.** NAD+ is part of core cell metabolism and DNA repair, and researchers are still working out how NAD+ levels relate to cancer biology. Long-term safety data for injected NAD+ are not available, so raise any cancer history with your provider. - **Other medications or ongoing conditions.** Share every prescription, supplement and diagnosis, including liver, kidney or heart conditions, so your provider can judge whether NAD+ fits. - **Past allergic reactions** to injectable medications or their ingredients. ## When to call your provider, and when to get urgent care ### Message your provider if you notice 1. Injection-site redness, warmth or swelling that spreads or lasts more than a day or two. 2. Pus, increasing pain or a fever, which can point to infection. 3. Nausea, headache or fatigue that keeps coming back after each dose. 4. Lightheadedness that makes daily tasks hard. 5. Any reaction that worries you, even if it seems small. ### Get emergency care for - Hives or a rash spreading across the body. - Swelling of the face, lips, tongue or throat. - Trouble breathing or chest pain. - Fainting or a racing heartbeat. Never change your own dose to manage side effects. Dose and schedule are set by your prescriber. Our [NAD+ injection dosage guide](https://www.telosrx.com/blogs/hormone-longevity/nad-injection-dosage-guide) explains how providers set and adjust them. ## How the telos rx care team supports you telos rx is an online-first, asynchronous telehealth service. You complete a roughly 5-minute online visit, and a licensed provider reviews it without a scheduled appointment. Every prescription is subject to medical approval by a licensed provider, and you pay nothing if you are not approved. If you are prescribed NAD+, it is offered as a needle-free nasal spray or a subcutaneous injection, and your provider helps you pick. Once you start, support continues: - **Unlimited care-team messaging** for side effects or questions. - **Dose adjustments** by your provider when needed. - **Quarterly labs** to keep an eye on your health. - Filled by licensed US partner pharmacies, with free 2-day shipping and discreet packaging. - FSA/HSA eligible, cancel anytime, from as low as $116 per month. See both formats on the [telos rx NAD+ page](https://www.telosrx.com/pages/nad-nasal-spray). Compounded NAD+ is not FDA-approved, and it has not been evaluated by the FDA for safety, effectiveness or quality. ## Frequently asked questions ### What are the most common NAD injection side effects? The most commonly reported are injection-site reactions such as stinging, redness, soreness or mild swelling, along with flushing, nausea, headache, fatigue or lightheadedness. They are usually described as mild and short-lived. Human research on injected NAD+ is limited, so reliable frequency figures are not available. ### Why does a NAD+ shot sting? Stinging during the push is one of the most commonly reported NAD+ injection reactions. A slow, steady push and rotating injection sites are often recommended to ease it. If burning is severe, lasts for hours or comes with spreading redness, contact your provider. ### Are NAD injection side effects worse than IV? The two are hard to compare directly because human evidence for both is limited. Injections bring injection-site reactions, while IV involves a cannula and a long, clinic-paced session. A small 2019 pilot study reported no adverse events during a slow 6-hour IV infusion, but it did not test injections. ### Does a NAD+ nasal spray have fewer side effects? A nasal spray avoids needles, so there are no injection-site reactions. It can cause nasal irritation, stinging or a runny nose instead. Human data on intranasal NAD+ are also limited. Your provider can help you decide which route suits you. ### Who should not get NAD+ injections? There are not enough safety data for use during pregnancy or breastfeeding. Anyone with a current or past cancer diagnosis, other medications, ongoing medical conditions or past reactions to injectable medications should discuss it with a provider first. Every prescription is subject to medical approval by a licensed provider. ### When should I call my provider about a side effect? Message your provider about reactions that spread, last more than a day or two, return after every dose, or worry you. Seek emergency care for hives, swelling of the face or throat, trouble breathing, chest pain or fainting. Do not change your dose on your own. Ready to talk it through? Complete a short online visit, and a licensed provider will review whether NAD+ fits you, injection or spray. You pay nothing if you are not approved. [Start your online visit](https://www.telosrx.com/pages/lp8nad) _This article is for general education and is not medical advice. Compounded NAD+ is not FDA-approved and has not been evaluated by the FDA for safety, effectiveness or quality. Prescriptions are subject to medical approval by a licensed provider; approval is not guaranteed. Individual experiences vary. telos rx is a LegitScript-certified, online-first, asynchronous telehealth service._ **Tags:** Longevity, NAD+, NAD+ injection, NAD+ side effects --- > Source: [Telos RX](https://www.telosrx.com/blogs/hormone-longevity/nad-injection-side-effects)