Coenzyme / pyridine nucleotide (not a peptide)

Nicotinamide adenine dinucleotide. Not a peptide — included in the encyclopedia because it overlaps heavily with peptide stacks and the same regulatory landscape. Distinct from precursors NMN and NR.

NAD+

Last verified: 2026-04-28

Note: NAD+ is not a peptide. It is a coenzyme, included in this encyclopedia because it overlaps heavily with peptide stacks, biohacker protocols, and the same regulatory grey areas that surround injectable peptides. The “At a glance” rows below are adapted accordingly — there is no amino-acid sequence to report.

At a glance

Also known as	Nicotinamide adenine dinucleotide, β-NAD+, NAD (reduced form: NADH)
Class	Coenzyme / pyridine nucleotide — not a peptide
Form	NAD+ itself (IV, subQ, intranasal, sublingual). Distinct from precursors NMN, NR, and niacinamide, which the body converts to NAD+.
Common delivery products	IV drip (most clinical use), subcutaneous injection vials, intranasal spray, sublingual troches/films, oral NMN or NR capsules (precursors, not NAD+)
Typical route	IV infusion (clinic), subQ injection (research-chemical and home-protocol use), oral precursor (consumer supplement)
Half-life	NAD+ is degraded rapidly in plasma (minutes); cellular NAD+ pool turnover varies by tissue, hours to days. PK is genuinely complex because the molecule is consumed by enzymatic reactions, not just cleared.
Molecular weight	NAD+: 663.4 Da. NMN (precursor): 334.2 Da. NR (precursor): 255.2 Da.

What it is

NAD+ is a coenzyme — a small molecule that enzymes need in order to do their job — present in every living cell. It is essential to energy metabolism (the conversion of food into ATP), and is also a substrate for sirtuins, PARPs, and CD38 enzymes that regulate gene expression, DNA repair, and immune signalling. It is not a peptide. It is included here because the peptide community treats NAD+ and its precursors as adjacent territory, and because the regulatory/safety landscape mirrors injectable peptides closely.

NAD+ levels in tissue decline with age — the commonly cited figure is roughly halving every 20 years from young adulthood, though absolute values are tissue-dependent and methods vary. The biohacker thesis is that raising NAD+ levels back toward youthful values yields anti-aging benefit. The evidence for the raising part is reasonable for some routes; the evidence for the anti-aging benefit part remains thinner than the marketing implies.

The market is fragmented across three different molecules that are often conflated:

• NAD+ itself — usually given by IV or subQ injection, sometimes intranasal or sublingual
• NMN (nicotinamide mononucleotide) — one step upstream; oral capsule is the dominant form
• NR (nicotinamide riboside) — two steps upstream; oral capsule is the dominant form (Niagen is the trade name)

A bottle labelled “NAD+” in a consumer supplement is almost always NMN or NR, not NAD+. This is the single most common source of user confusion.

Mechanism

NAD+ functions in two distinct modes that matter for understanding the claims around it:

Redox cofactor. NAD+ accepts electrons during catabolism (turning into NADH), then NADH donates electrons to the electron transport chain to drive ATP synthesis. This is the classical biochemistry-textbook role. Cellular energy production depends on a sufficient NAD+/NADH pool.

Substrate consumption. NAD+ is consumed (not just recycled) by three major enzyme families:

• Sirtuins (SIRT1–SIRT7) — deacetylases that regulate gene expression, mitochondrial biogenesis, and stress response. Implicated in many longevity pathways.
• PARPs (poly-ADP-ribose polymerases) — DNA repair enzymes activated by damage; heavy users of NAD+.
• CD38 — an immune-related enzyme that becomes a major NAD+ consumer in inflammation and aging tissue.

The longevity argument is roughly: aging tissue has more inflammation, more DNA damage, and higher CD38 activity, which depletes NAD+, which limits sirtuin function, which feeds further dysfunction. Raising NAD+ targets this loop.

Precursor pathways (relevant because most consumer products are precursors, not NAD+):

• NR → NMN → NAD+ (salvage pathway, the most-studied oral route)
• NMN → NAD+ (one step shorter; ongoing debate about whether NMN crosses cell membranes intact or is dephosphorylated to NR first)
• Niacin (NA) and niacinamide → NAD+ via different pathways

Distinguish demonstrated in humans from demonstrated in rodents. Many sirtuin / lifespan extension findings come from yeast, worms, and mice. Human translation is partial and contested.12

Routes of administration

NAD+ has more route variety than any peptide in this encyclopedia, and doses absolutely do not translate across them. A 250 mg subQ injection of NAD+ is not equivalent to 250 mg oral NMN.

Intravenous infusion (clinic)

Bioavailability	~100% (direct to circulation)
Onset	Minutes (intracellular uptake follows over hours)
Duration	Plasma NAD+ degraded over hours; tissue effects on cellular NAD+ pool variable, typically days
Typical dose (this route)	250–1,000 mg per infusion; some clinics escalate to 1,500 mg over multi-hour drips
Equipment	Clinical IV setup, trained nurse/practitioner, vital-sign monitoring
When this route makes sense	Clinical settings where flushing/discomfort can be managed actively. Often marketed for energy, cognition, addiction recovery support, and anti-aging.

The most evidence-rich and most uncomfortable route. Flushing, chest tightness, nausea, headache, and a wave-like sensation of pressure are extremely common during NAD+ IV — these are dose-rate-dependent and reduce when the drip is slowed. Standard clinic practice is 2–4 hours per infusion to keep symptoms manageable.6 Some clinics co-administer vitamin C, magnesium, or B-vitamins to dampen the niacin-flush effect.6

The proposed mechanism for the IV-specific symptoms is partial conversion of NAD+ to nicotinic acid (niacin) during infusion, which triggers prostaglandin-mediated vasodilation. This is the same physiological mechanism as the well-known niacin flush.6

Cost is significant. A single 500–1,000 mg drip in a UK or US wellness clinic typically runs £150–£500+ per session. Multi-session protocols (often 4–10 infusions over weeks) push total cost into four figures.

Subcutaneous injection

Bioavailability	High (claimed near-100% systemic, though formal human PK data is limited); slower entry to circulation than IV
Onset	1–2 hours to plasma peak; cellular effects develop over hours to days
Duration	Plasma peak followed by ~8–12 hour level (community-reported, not formally characterised)
Typical dose (this route)	Community ranges of 50–200 mg per injection, 2–7× weekly. Often a “loading phase” (daily for 1–2 weeks) followed by a maintenance schedule. These are observations, not recommendations.
Equipment	Insulin syringe (U-100), pre-mixed vials (NAD+ is not typically reconstituted from powder at home — it is supplied pre-dissolved)
When this route makes sense	Users who want IV-like systemic delivery without the cost and time of clinic infusions, accepting less complete PK characterisation

The research-chemical and clinic-prescribed home-protocol route. Less acute discomfort than IV because the dose is smaller and absorption is slower, but injection-site stinging is common (NAD+ solutions are typically acidic) and many users report the same flushing/pressure sensations at higher doses.

NAD+ is unstable in solution — products are usually pre-formulated with stabilisers and require refrigeration. This is unlike most peptides, where lyophilised powder + bacteriostatic-water reconstitution is the standard pattern.

Intranasal spray

Bioavailability	Not formally characterised in humans
Onset	15–45 minutes claimed; not validated by published PK
Duration	Not formally characterised
Typical dose (this route)	Compounded sprays usually deliver 50–100 mg per dose
Equipment	Compounded nasal spray
When this route makes sense	Users avoiding injection; often combined with a separate IV/subQ protocol rather than as primary route

Marketed for cognition and convenience. The molecule’s size and polarity make significant nasal absorption plausible but not well-quantified. Treat any specific PK numbers from product sites with scepticism.

Sublingual troches / films

Bioavailability	Modest; bypasses first-pass hepatic metabolism but oral mucosal absorption of large polar molecules is limited
Onset	30–60 minutes
Duration	Variable
Typical dose (this route)	50–250 mg per troche
Equipment	None — dissolves under the tongue
When this route makes sense	Convenience and cost; less steep efficacy than IV/subQ

Most accessible non-injection route. Effect is more modest than injection forms but the user experience is much easier.

Oral precursors (NMN, NR)

Bioavailability	NR: well-established to raise blood NAD+ (multiple human trials). NMN: similar magnitude in head-to-head comparisons; gut bacterial conversion plays a role.12 Oral NAD+ itself is largely degraded — bottles labelled “oral NAD+” are usually NMN, NR, or niacinamide.
Onset	Days for measurable blood NAD+ rise; weeks before any claimed clinical effect
Duration	Continuous dosing required; blood NAD+ falls when supplementation stops1
Typical dose (this route)	NMN: 250–500 mg/day common; up to 1,000 mg in some trials. NR: 250–1,000 mg/day.
Equipment	None — capsule or powder
When this route makes sense	Lowest-friction, lowest-cost route. The bulk of human RCT evidence for NAD+ precursors is here.

This is where the human-trial evidence base is strongest. Direct comparison studies show NMN and NR roughly double circulating NAD+ over ~2 weeks; nicotinamide does not produce the same effect.12 Whether that translates to clinical benefit is mixed: a 2024–2025 meta-analysis found negligible muscle-mass effect across NMN and NR trials, while specific subgroups (older adults, peripheral artery disease, long COVID) show modest signals.13

Cross-route comparison. IV is the most direct and the most uncomfortable. SubQ is a middle ground. Oral precursors have the strongest controlled-trial base for raising NAD+ levels but not necessarily for clinical anti-aging benefit. Doses do not translate across routes — a 1,000 mg NMN capsule and a 1,000 mg NAD+ IV are not the same intervention. Sublingual and intranasal are convenience routes with weak PK validation.

What the evidence says

Honest picture, by claim:

• “NAD+ precursors raise blood NAD+ levels” — well-supported. Multiple RCTs show NMN and NR roughly double circulating NAD+ over 2–4 weeks.12
• “NAD+ precursors improve muscle function in older adults” — mixed. Recent meta-analysis found negligible overall effect across NMN and NR trials, with possible benefit in specific subgroups.3
• “NAD+ improves sleep / walking speed in older adults” — modest support from one 250 mg/day NMN RCT in adults 65–75.1
• “NR helps long-COVID symptoms” — single-centre RCT (n=58) at 2,000 mg/day for 20 weeks reported some benefit on cognition; not yet replicated.3
• “NAD+ IV reverses aging” — overstated. No RCT supports this framing. The mechanism is plausible at the cellular level; clinical evidence at the lifespan-or-healthspan level is essentially absent in humans.
• “NAD+ helps addiction recovery” — clinic-marketed; very limited controlled data.
• “Subcutaneous NAD+ has IV-equivalent effects” — claimed; not formally characterised in published human PK.

The pattern: precursor PK is solid, clinical-benefit data is mixed and condition-specific, and the strongest anti-aging claims live further from the evidence than the marketing suggests.

Typical use patterns

What users do (frame as observation):

Clinic IV protocols:

• 500–1,000 mg per infusion, 2–4 hour drip
• Loading: 4–10 infusions over 2–6 weeks
• Maintenance: monthly or quarterly

Home subQ protocols:

• 50–100 mg per injection, 3–7× weekly
• Loading phase (daily, 1–2 weeks) common, then taper to 1–3× weekly
• Often cycled (4–6 weeks on, 1–2 weeks off)

Oral precursors (NMN, NR):

• NMN: 250–500 mg/day, often AM with food
• NR: 300–1,000 mg/day; Niagen (the branded NR) typically 300 mg
• Continuous dosing — effects regress when stopped1

Stacking patterns:

• Often paired with resveratrol or pterostilbene (the “sirtuin activator” framing) — note that the human evidence for resveratrol synergy is much weaker than the rodent data
• TMG (trimethylglycine) is commonly added to NMN/NR protocols to provide methyl donors, on the theory that high NAD+ throughput depletes methyl groups; the methyl-depletion hypothesis itself is not well established in humans
• Combined with peptide stacks (BPC-157, TB-500, GHK-Cu) for “regeneration” framing

For sensitive systems

The sub-audience this encyclopedia explicitly serves: people with MCAS, histamine intolerance, UARS, POTS, long COVID, autoimmune conditions, ME/CFS, PMDD, or otherwise hyperreactive nervous/immune systems.

NAD+ is genuinely complicated for this population, and it is one of the compounds where standard biohacker protocols (high-dose IV, fast drips) can actively harm people with sensitive nervous systems and dysautonomia.

• Niacin-flush response: any route that delivers NAD+ fast enough can trigger prostaglandin-mediated flushing, which in POTS or MCAS patients may cascade into a much larger response — drop in blood pressure, mast cell degranulation, full-body flush. In clinic reports, slowing the infusion rate is the main way symptoms are managed; some clinicians avoid NAD+ IV in known POTS patients.
• Histamine route: NAD+ feeds enzymes (including PARPs and DAO-related pathways) that intersect with histamine metabolism in complex ways. Some MCAS patients tolerate it well; others flare badly.
• Cautious-introduction reports (subQ): sensitive users commonly describe starting well below the 100–200 mg community default, often around 25–50 mg, then holding steady long enough to watch for flushing, fatigue, or dysautonomia symptoms. This is an observed harm-reduction pattern, not a recommended protocol.
• Cautious-introduction reports (oral precursor): sensitive users often report starting below standard supplement-label dosing, then increasing only if sleep, histamine, and PEM patterns remain stable. Methyl-donor support is sometimes discussed in this context, but the methyl-depletion hypothesis is not well established in humans.
• Route sensitivity: IV is a high-intensity introduction route for sensitive-systems users. Oral precursor or lower-dose subQ reports are generally described as easier to stop and reverse if symptoms appear.
• Pre-planning: sensitive users often define stop criteria in advance and discuss rescue medication plans with a clinician rather than improvising during a reaction.
• Stop criteria: persistent flushing across multiple doses, escalating fatigue or PEM (post-exertional malaise) in ME/CFS users, palpitations or pre-syncope in POTS users, breathing changes.
• Energy is not always positive: ME/CFS patients in particular sometimes report a “stimulation” response that triggers crashes. The mechanism is unclear but the pattern is consistent enough to take seriously.

This is an area where the standard “loading phase, then maintenance” framing may be unsuitable. A long, gentle ramp on oral precursors is often safer than any injection protocol.

Reasonable expectations

What to actually expect:

• Onset: subjective “energy” effects from IV can appear during or shortly after the drip; oral precursor effects on blood NAD+ take 1–2 weeks; subjective effects (if any) typically take 4–8 weeks
• Response rate: clinical trial endpoints (sleep, walking speed, NAD+ levels) show majority response on biochemical markers but mixed response on functional outcomes
• What the literature actually supports: precursors raise blood NAD+ levels reliably; specific clinical benefits in specific populations have modest support; broad anti-aging benefits in healthy adults are not well supported
• What not to expect: dramatic anti-aging effects, “feeling 20 years younger,” reversing established disease, or matching the claims on clinic websites

The honest read: NAD+ raises a measurable biomarker, that biomarker matters biologically, and the clinical translation is less impressive than the underlying biochemistry suggests.

Cost

IV infusion (single session)	£150–£500+ at UK wellness clinics, depending on dose
IV infusion course (4–10 sessions)	£600–£5,000+
Home subQ (research-chemical)	£40–£100 per multi-dose vial; per-month cost £40–£200 depending on protocol
Oral NMN (250–500 mg/day)	£25–£60 per month from reputable supplement brands
Oral NR (300–1,000 mg/day)	£30–£80 per month; Niagen-branded NR sits at higher end
Cost per month at sensitive-start doses	£15–£30 (oral precursor); minimal additional cost for the smaller subQ doses

No vendor names, no affiliate links. The cost gap between IV and oral routes is dramatic — by orders of magnitude. The evidence quality favours oral precursors for the cost.

Reconstitution

NAD+ is typically supplied pre-formulated in solution rather than as lyophilised powder, because it is unstable in dry storage at scale and degrades rapidly once dissolved. Vials require refrigeration (some require freezing) and have shorter shelf lives than peptide products — often 30–60 days after opening, days to weeks once drawn into a syringe.

This is a significant practical difference vs the peptides covered elsewhere in this encyclopedia. There is no “reconstitute 50 mg vial with 2 mL BAC water” pattern for NAD+.

Open the Vial Plan calculator

For oral precursors (NMN, NR), no reconstitution applies — capsule or powder.

Areas of concern ⚠

This is a compound where the biology is strong, the biochemistry of effect on NAD+ levels is established, and the clinical translation is where the marketing routinely overreaches.

Safety signals

• Acute infusion symptoms are very common: flushing, chest tightness, nausea, headache, abdominal pressure, anxiety. These are dose-rate-dependent rather than dose-total-dependent.6
• Long-term human safety data is limited for high-dose chronic NAD+ administration (IV or subQ). Oral NR has the strongest long-term safety record at supplemental doses.
• Theoretical cancer concern: PARPs and CD38 are upregulated in some tumours, and a few preclinical studies have raised the question of whether elevated NAD+ could fuel tumour growth in established malignancy. Counter-evidence exists. Honest summary: probably fine in healthy people, genuinely uncertain in active or recent cancer; users with cancer history should treat this as a contraindication until clearer human data exists.

Quality and sourcing

• Oral NMN and NR: third-party-tested products from established supplement brands are generally reliable. Cheap unregulated NMN has been documented to contain substantially less active ingredient than labelled.
• Injectable NAD+: clinic-supplied is usually compounded by licensed pharmacies in the US and parts of Europe; quality is reasonable. Research-chemical injectable NAD+ is rare and harder to verify than peptide research-chems.
• NAD+ is unstable — refrigeration is mandatory for solution products, and a colour change or precipitate suggests degradation.

Regulatory and sport

• NMN (US, FDA): As of September 2025 the FDA reversed its 2022 position and confirmed NMN is lawful as a dietary supplement.45 The 2022 position had excluded NMN under the “drug preclusion” provision; the 2025 reversal acknowledges NMN was marketed as a supplement before drug investigation. This is a recent, material change — older “NMN is FDA-banned” claims online are now out of date.
• NR (US, FDA): continuously lawful as a dietary supplement (Niagen has full NDI/GRAS status).
• NAD+ injection (US, FDA): not an approved drug; clinic IV protocols typically rely on compounded preparations. The 2026 FDA peptide review did not specifically address NAD+ but tightened the broader compounding landscape.
• UK (MHRA), EU (EMA): NMN supplement status varies by country; UK has been more permissive than some EU member states. Injectable NAD+ for human use is not approved as a medicine; clinic use is via private compounding.
• WADA (sport): NAD+ and its precursors are not on the prohibited list as of the 2026 list. Athletes should still verify the current annual list.

Drug and supplement interactions

• Methylation-relevant medications: high-dose NMN/NR may increase methyl-group demand; users on SAMe, methylated B-vitamins, or methylation-sensitive medications (e.g. some psychiatric drugs) should pay attention to symptoms
• Resveratrol / pterostilbene are commonly stacked but the human synergy data is weak
• Niacin or nicotinamide supplements stacked with NMN/NR effectively double-dose the NAD+ pathway
• Some chemotherapy and PARP-inhibitor regimens intersect directly with NAD+-dependent pathways — explicit oncology contraindication territory

Populations where caution is warranted

• Pregnancy and breastfeeding — no data, default contraindication
• Active or recent malignancy — theoretical concern; treat as an exclusion-level issue unless an oncology clinician explicitly advises otherwise
• Severe MCAS, POTS, or dysautonomia — IV is the highest-friction route; clinician-supervised rate control matters if this route is used
• Under 18 — no data; not appropriate without specific clinical reason
• Methylation disorders — careful titration, methyl-donor support if symptoms emerge

Measurement and dosing pitfalls

• The biggest error is route confusion: oral NMN dose ≠ subQ NAD+ dose ≠ IV NAD+ dose. They are not interchangeable.
• Bottles labelled “NAD+” are often NMN or NR. Read the actual ingredient.
• NMN vs NR are not the same molecule. Effects are similar in head-to-head trials but pharmacokinetics differ.12
• Refrigeration matters. Solution products left at room temperature lose potency quickly.

What the community often gets wrong

• “NAD+ reverses aging.” It raises a biomarker linked to aging; clinical lifespan/healthspan benefit in humans is not established.
• “Resveratrol activates sirtuins, so stack it with NAD+.” The sirtuin-activation hypothesis for resveratrol in humans is much weaker than the rodent data.
• “More is better.” No, especially not for IV — symptom severity scales with dose rate.
• “NMN is FDA-banned.” Out of date as of September 2025.
• “Oral NAD+ supplements work.” Almost always those are NMN or NR; oral NAD+ itself is largely degraded.

FDA / regulatory status

Jurisdiction	Status	Last verified
US (FDA) — NMN	Lawful as a dietary supplement as of FDA reversal, September 202545	2026-04-28
US (FDA) — NR	Lawful as a dietary supplement (long-standing NDI/GRAS status)	2026-04-28
US (FDA) — injectable NAD+	Not an approved drug. Compounded preparations supplied through licensed pharmacies; legal posture follows general compounding rules.	2026-04-28
UK (MHRA)	NMN/NR supplements: permissive but country-by-country in EU. Injectable NAD+ is not an approved medicine; clinic use via private compounding.	2026-04-28
EU (EMA)	NMN status varies by member state; NR more uniformly permitted. Injectable NAD+ not approved as a medicine.	2026-04-28
WADA (sport)	Not on the 2026 prohibited list; recheck the current annual list.	2026-04-28

Narrative: The single most important regulatory event for NAD+ in recent memory is the FDA’s September 2025 reversal on NMN — moving it from a “prohibited dietary ingredient” position back to lawful supplement status.45 This change is recent enough that older articles online still describe NMN as FDA-banned. Injectable NAD+ remains in the same general compounding regime as injectable peptides and is subject to the same broader regulatory tightening seen across the 2026 FDA peptide review, though NAD+ itself was not specifically named in those proceedings.

What to track in Peptrax

NAD+ is the compound in this encyclopedia where the cost-per-effect spread between routes is most extreme — a single IV session can cost more than a year of oral NMN — and where the marketing leans hardest on a biomarker (raised blood NAD+) that doesn’t always translate to felt benefit. The most valuable thing the app can do here is help you see your answer to that translation question.

For IV and subQ users, the headline signals are dose-rate tolerability and felt effect over the days following an infusion or injection. Logging acute symptoms (flushing, chest tightness, nausea, pressure) against drip rate or injection size lets you find the rate where you actually tolerate the dose, rather than enduring a generic clinic protocol. Then over the 24–72 hours after each dose, energy, sleep, cognition, and HRV are the felt-experience signals that either back up the spend or quietly suggest the biomarker rise isn’t doing much for you. Cost per session against that felt-effect rating is the honest read; without it, it’s easy to spend £2,000 on a 6-session course and never check whether anything changed.

For oral precursor users, the timescale is longer and the question is different: did 8–12 weeks of consistent NMN or NR change baseline energy, sleep, or recovery enough to justify the monthly spend? If you’re in a sensitive-systems group (POTS, ME/CFS, MCAS), watching for PEM or histamine flares is the higher-priority signal — gentle ramps and a clear stop criterion are safer than the standard loading-phase pattern, and the app’s job is to make those patterns visible early.

Across all routes, the form is a first-class fact: NAD+, NMN, NR, and niacinamide are not interchangeable, and people regularly mix them up. Recording which molecule, at what dose, by what route, alongside any methylation-support stack (TMG, B-vitamins) is what makes a later “did this actually do anything” review possible.

For personal tracking and informational purposes only — not medical advice.

Sources

1. Scientists Unveil Results from Human Trial Directly Comparing Three NAD+ Precursors — NMN.com news summary (secondary source; aggregates 2024–2025 head-to-head trial data)
2. An Updated Review on the Mechanisms, Pre-Clinical and Clinical Comparisons of Nicotinamide Mononucleotide (NMN) and Nicotinamide Riboside (NR) — Yang, Food Frontiers 2025
3. Effects of nicotinamide riboside on NAD+ levels, cognition, and symptom recovery in long-COVID: a randomized controlled trial — Brouwer et al., eClinicalMedicine 2025
4. FDA declares NMN lawful in dietary supplements — NutraIngredients, September 2025
5. FDA Reinstates NMN As Dietary Supplement After NPA Lawsuit — Natural Products Association
6. NAD+ IV Therapy Side Effects — Restore Hyper Wellness (secondary source; community/clinic-observation summary on infusion-rate side effects)
7. The Effect of Nicotinamide Mononucleotide and Riboside on Skeletal Muscle Mass and Function: A Systematic Review and Meta-Analysis — PMC12022230, 2025
8. WADA 2026 Prohibited List