NAD+ Injections: A Complete Guide to Benefits, Dosing & Protocol

What Is NAD+ and Why Does It Matter?#

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell in the body, playing a central role in energy metabolism and cellular repair. It is required for the activity of sirtuins (longevity-associated proteins), PARP enzymes (DNA repair), and the mitochondrial electron transport chain. NAD+ levels decline significantly with age — roughly 50% by middle age — and this decline is associated with reduced energy, impaired cellular repair, cognitive decline, and accelerated ageing. Restoring NAD+ levels has become one of the most researched approaches in longevity medicine.

NAD+ Injections vs. Oral Supplements#

Oral NAD+ precursors (NMN, NR) are the most popular and accessible supplementation route. However, oral bioavailability is inconsistent and absorption may be limited by gut bacteria that metabolise precursors before they reach systemic circulation. NAD+ injections bypass the digestive tract entirely — subcutaneous or intramuscular administration delivers the molecule directly into circulation, significantly increasing bioavailability. Clinical studies on injectable NAD+ show faster and more pronounced increases in blood NAD+ levels compared to oral supplementation.

Injections raise blood NAD+ levels significantly faster than oral NMN or NR supplements.

IV NAD+ Therapy vs. Subcutaneous Injection#

IV (intravenous) NAD+ therapy delivers high doses (500mg-1000mg+) directly into the bloodstream over 2-4 hours. Infusions produce rapid increases in NAD+ levels but are expensive ($300-$800+ per session) and require clinic attendance. Side effects during infusion (flushing, nausea, chest tightness) are common and limit the infusion rate. Subcutaneous injection is a more accessible alternative — doses of 25-100mg injected under the skin provide sustained absorption with a better side effect profile. Many at-home protocols use subcutaneous injection 3-5 days per week as a maintenance protocol after an initial IV loading period.

Dosing Protocol#

For subcutaneous injection, typical protocols range from 25mg to 100mg per injection, administered 3-7 days per week. A common starting approach is 50mg every other day for the first month, then adjusting based on response. IV protocols typically start with a series of 500mg infusions (3-5 sessions over 1-2 weeks) for loading, then monthly maintenance infusions or transition to subcutaneous self-administration. NAD+ powder must be reconstituted in bacteriostatic water. A 500mg vial in 5mL BAC water gives 100mg/mL. A 50mg dose = 0.5mL = 50 units on a U-100 syringe.

Expected Effects and Timeline#

Most users report increased energy, improved mental clarity, and better sleep within 1-2 weeks of starting injections. Athletic performance improvements and faster recovery are reported over weeks to months. Cognitive benefits — focus and memory — are among the most consistently reported effects. Longer-term effects on longevity biomarkers require sustained protocols of 3-6+ months to evaluate. Side effects are generally mild with subcutaneous administration: minor injection site reactions, occasional nausea. IV therapy has a more pronounced immediate effect but also more pronounced side effects during infusion.