NAD+ Injection Side Effects: IV Drips vs Shots Under the Skin or in Muscle

NAD+ IV drips tend to cause nausea, belly cramping, chest pressure and a fast heartbeat while the drip runs. NAD+ shots tend to cause a sore, red spot where the needle went in for one to four days, plus milder nausea, flushing, headache or tiredness.

Speed and amount explain much of the gap. One dramatic injection story raises real questions without showing how often severe reactions happen.

Why does an IV feel different from a shot?

A shot under the skin holds far less NAD+ than a drip into a vein. One review puts a typical shot at about 20 mg and a typical IV bag at 500 mg Goldman dose comparison. You feel that gap because the IV puts much more fluid into your blood over an hour or more.

In a 2026 retrospective pilot, six adults received commercial 500 mg NAD+ through a vein on four days in a row. All six reported moderate to severe belly cramping, diarrhea, nausea, vomiting, faster heart rate, throat pain, congestion and chest pressure while the fluid ran Frontiers pilot. Their drips ran about 97 minutes on average, and blood tests for liver, kidney, inflammation and thyroid showed no significant change. That pilot was tiny and looked back at records, so it cannot show how often these effects happen for every woman.

A 2026 clinical review lists nausea, flushing or warmth, headache, soreness where the needle went in, tiredness, dizziness and chest tightness with a drip as the most common effects Testing.com review. The same review notes that a faster drip or higher amount tends to cause more discomfort.

What happens with shots under the skin or in muscle?

Subcutaneous means a shot into the fatty layer under the skin. Intramuscular means a shot into muscle. Intravenous means a drip into a vein.

TrimRX, a telehealth provider, reports site reactions in 20 to 40% of its own patients getting shots under the skin or into muscle TrimRX site data. In its patient base, belly shots under the skin caused mild redness or tenderness in 25 to 35% and cleared in 24 to 48 hours. Shots into the shoulder muscle caused pain or warmth in 30 to 45% and cleared in 36 to 72 hours. Shots into the buttock muscle caused pain in 20 to 30% and cleared in 48 to 96 hours. Drips caused local vein irritation in under 5%. These are one provider’s rates, not a measure of what every woman will feel.

Shots can still cause whole body effects for hours after, most often flushing, headache and tiredness in addition to the sore spot Testing.com review. The review notes soreness at the site often clears in a day or two.

What women report

In r/cfs, rblythe wrote, “I looked at my heart rate and realized that it had shot up in moments from 85 bpm to 169 bpm (my normal heart rate for comparison is about 80 bpm laying down, up to 110 walking around, and 130 bpm with something harder like going up stairs).”

In the same r/cfs thread, rblythe wrote, “From the peak at 169 bpm heart rate about 5 min after the shot, it gradually came down to about 100 bpm after 30 minutes.”

In the same r/cfs thread, rblythe wrote, “For the past week I've been getting night sweats and my heart rate at night has been higher than it should be (by about 10-15 bpm).”

This person described a 100 mg shot followed by nausea, cramping and muscle aches plus a week of night sweats and higher resting heart rate. One frightening experience signals a question to bring to your clinician. It does not show how often severe effects happen. If you want help deciding whether an energy and longevity treatment fits your history and goals, you can start your HOD plan through /quiz.