An NAD+ IM injection goes into muscle with a longer needle, usually given in a clinic. A subcutaneous NAD+ injection goes into the fat just under the skin with a short, fine needle, which is why it is the route most often used at home. Human evidence comparing the two routes for NAD+ is limited, so the choice comes down to practicality, comfort and your provider's judgment.
If you have been searching "nad im injection" and seeing subcutaneous shots, IV drips and nasal sprays all mentioned in the same breath, this guide sorts them out. We cover where each injection goes, how the needles differ, who gives them, what general pharmacology says about absorption, and where the evidence simply runs out.
First, a quick refresher on NAD+
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell. It shuttles electrons in the redox reactions behind energy metabolism, and it is used up by enzymes such as sirtuins, PARPs (involved in DNA repair) and CD38, as summarised in this review of NAD+ metabolism and ageing.
It is not a peptide, a vitamin or a hormone. Swallowed NAD+ is largely broken down in the gut, which is why supplements usually sell precursors instead. That is also why people look at injections in the first place. For the full background, start with our NAD+ injection guide.
NAD IM injection vs subcutaneous injection: the core difference
Both are injections. The difference is the depth of tissue the medicine is delivered into.
Intramuscular (IM)
- Where it goes: into a muscle, commonly the upper arm (deltoid), the outer thigh or the buttock (gluteal muscle).
- Needle: longer and often thicker, so it can pass through skin and fat to reach muscle.
- Who gives it: usually a nurse or clinician in a clinic or wellness setting.
Subcutaneous (subQ)
- Where it goes: into the fat layer just under the skin, commonly the abdomen or the front of the thigh.
- Needle: short and fine, similar to an insulin syringe.
- Who gives it: commonly self-administered at home after instructions from a provider or pharmacy.
A subcutaneous injection is the same technique many people already know from insulin and other at-home medicines. We go deeper on this route in NAD+ subcutaneous injection explained.
Absorption: what general pharmacology says
In general pharmacology, muscle has a richer blood supply than fat. For many drugs, that means an IM injection reaches the bloodstream somewhat faster than a subcutaneous one, while a subcutaneous injection tends to be absorbed more gradually. IV delivery skips absorption entirely by going straight into a vein.
Here is the honest caveat: those are general principles, not NAD+-specific findings. We are not aware of published human studies that directly compare how NAD+ is absorbed after IM versus subcutaneous injection. Anyone quoting precise absorption percentages for NAD+ by route should be asked where the number comes from.
What human data do exist mostly cover IV infusion and oral precursors. In one small pilot study of IV NAD+, eight healthy men received 750 mg of NAD+ over six hours. The researchers reported that NAD+ was rapidly removed from plasma for at least the first two hours, and they observed no adverse events during the infusion. Even that study tells us little about injections under the skin or into muscle.
Faster absorption also is not automatically better. How the body handles NAD+ once it is in circulation is still being studied, which is part of why your provider, not the route with the quickest uptake, should guide the decision.
Weighing a needle against a needle-free option? A licensed provider can review your health history online and help you choose the route that fits.
See if NAD+ is right for youComfort and side effects by route
Comfort is where the two injection routes feel most different in everyday life.
- Needle feel: a short, fine subQ needle is usually less intimidating than a longer IM needle.
- Stinging: NAD+ is often reported to sting on injection, whichever route is used. A slow push is commonly recommended.
- Soreness: IM injections can leave the muscle feeling achy afterwards. SubQ injections more often leave a small area of redness or a little bump.
Commonly reported reactions to NAD+ injections include redness, soreness or swelling at the injection site, flushing, nausea, headache, fatigue and lightheadedness. These are reported reactions, and how often they happen has not been well measured for either route. Our NAD+ side effects guide covers what to watch for and when to contact your provider.
Practicality for at-home use
This is where subcutaneous injection pulls clearly ahead for most people.
- Self-injection: subQ technique is simple to learn. Reaching a deltoid or gluteal muscle correctly on yourself is harder.
- Site rotation: the abdomen and thighs give plenty of room to rotate subQ sites.
- Supplies: small insulin-style syringes, alcohol swabs and a sharps container are usually all that is needed.
- No clinic visits: IM NAD+ is more often given in person, which means appointments and travel.
If you are prescribed injections, our step-by-step guide to subcutaneous NAD+ injection walks through each step. Always follow your own prescription and pharmacy label.
IM vs subQ vs nasal spray vs IV at a glance
| Intramuscular (IM) | Subcutaneous (subQ) | Nasal spray | IV infusion | |
|---|---|---|---|---|
| Where it goes | Muscle (deltoid, thigh, glute) | Fat under the skin (abdomen, thigh) | Lining of the nose | Directly into a vein |
| Needle | Longer needle | Short, fine needle | None | IV line |
| Who gives it | Usually a clinician | Often self-given at home | Self-given at home | Clinic staff |
| Time per dose | Minutes, plus a visit | Minutes | Seconds | Often hours |
| Human NAD+ evidence | Limited | Limited | Limited | Small pilot studies |
| Offered by telos rx | No | Yes | Yes | No |
For the infusion side of the story, read NAD+ injection vs IV therapy.
The evidence gaps, stated plainly
It is worth being direct about what is not known yet:
- There are few published human studies of subcutaneous or intramuscular NAD+.
- We are not aware of head-to-head human trials comparing IM and subQ NAD+.
- Human data on intranasal NAD+ are also limited.
- Most published human NAD+ research involves IV infusion or oral precursors such as nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN).
So no route can honestly be called "proven best." What can be compared with confidence is the practical side: needle size, who gives it, comfort and convenience.
Why telos rx prescribes subcutaneous or nasal NAD+
telos rx is built for at-home care, so we offer the two routes that fit it: a subcutaneous injection and a needle-free nasal spray. You can see both on our NAD+ product page, with pricing as low as $116 per month.
SubQ uses a short needle you can learn to use yourself. The nasal spray skips needles and sharps entirely. Your provider helps you choose based on your health history, comfort with needles and goals. The route, dose and technique are always set by your prescribing provider and the pharmacy instructions.
Here is how it works. You complete a roughly 5-minute online visit. A licensed provider reviews it asynchronously, 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 approved, your medication is filled by licensed US partner pharmacies and shipped free in 2 days in discreet packaging. Plans are FSA/HSA eligible, include unlimited care-team messaging, dose adjustments and quarterly labs, and you can cancel anytime.
Compounded NAD+ is not FDA-approved, and it has not been evaluated by the FDA for safety, effectiveness or quality.
Subcutaneous or needle-free, the first step is the same: a short online visit reviewed by a licensed provider.
Start your online visitFrequently asked questions
Is an NAD IM injection better than a subcutaneous injection?
Not necessarily. Muscle generally absorbs medicines faster than fat, but there are no head-to-head human studies comparing IM and subcutaneous NAD+. Subcutaneous injections are easier to give yourself at home. Your provider decides which route suits you.
Where are NAD+ subcutaneous injections given?
Subcutaneous NAD+ injections go into the fat layer just under the skin, most commonly on the abdomen or the front of the thigh. Sites are usually rotated each time. Always follow the site guidance from your provider and pharmacy.
Can I give myself an intramuscular NAD+ injection?
IM injections use longer needles and are harder to place correctly on yourself, so they are usually given by a clinician. Only use the route, needle and dose listed on your prescription. Ask your provider or pharmacist if anything is unclear.
Do NAD+ injections hurt?
Many people report a brief sting, and NAD+ is known for stinging as it goes in. A slow push is commonly recommended. Redness, soreness or a small bump at the site are reported reactions. Contact your provider if pain is severe or lasts.
Is there a needle-free alternative to NAD+ injections?
Yes. telos rx offers prescription NAD+ as a needle-free nasal spray as well as a subcutaneous injection. Human evidence for the intranasal route is limited, as it is for injections. A licensed provider helps you choose.
Is compounded NAD+ FDA-approved?
No. Compounded NAD+ is not FDA-approved and has not been evaluated by the FDA for safety, effectiveness or quality. It is prescribed by a licensed provider and prepared by a licensed pharmacy for an individual patient.
telos rx is LegitScript-certified and operates as an online-first, asynchronous telehealth service. Compounded NAD+ is not FDA-approved and has not been evaluated by the FDA for safety, effectiveness or quality. All prescriptions are subject to medical approval by a licensed provider; approval is not guaranteed. Individual results vary. This article is for general education and is not medical advice.