NAD injections deliver nicotinamide adenine dinucleotide—a vital coenzyme involved in cellular energy production and metabolism—directly into the body via intramuscular or intravenous routes. Whilst NAD+ plays well-established biochemical roles in mitochondrial function, DNA repair, and cellular stress responses, NAD injections remain unlicensed medicines in the UK with no MHRA-approved indications. They are primarily available through private clinics, often marketed for energy enhancement, cognitive support, and anti-ageing purposes. However, robust clinical evidence supporting these claims is limited, and the treatments are not recognised as evidence-based medicine by NICE or prescribed within the NHS.

What Are NAD Injections and How Do They Work?

NAD (nicotinamide adenine dinucleotide) is a coenzyme found in all living cells that plays a fundamental role in cellular metabolism and energy production. NAD injections deliver this molecule directly into the body, typically via intramuscular or intravenous routes.

NAD exists in two forms within cells: NAD+ (oxidised form) and NADH (reduced form). These molecules are essential cofactors in redox reactions, particularly in the mitochondrial electron transport chain where they facilitate ATP (adenosine triphosphate) production—the primary energy currency of cells. NAD+ also serves as a substrate for several enzyme families, including sirtuins, poly(ADP-ribose) polymerases (PARPs), and CD38, which regulate processes such as DNA repair, gene expression, and cellular stress responses.

As we age, cellular NAD+ levels naturally decline, a phenomenon observed across multiple tissues and associated with various age-related physiological changes. This decline has prompted interest in NAD+ supplementation as a potential intervention. NAD injections aim to increase NAD+ levels, though it's important to note that exogenous NAD+ may be degraded extracellularly, and human pharmacokinetics, tissue uptake, and optimal dosing remain uncertain.

It is crucial to understand that NAD injections are unlicensed medicines in the UK with no MHRA-approved indications or Summary of Product Characteristics (SmPC). The quality, purity, and sterility of compounded preparations may vary between providers. While the biochemistry of NAD+ is well established, the clinical significance of exogenous NAD+ administration remains an area of ongoing research, and there is currently limited robust evidence supporting many therapeutic claims associated with NAD injections in clinical practice.

Potential Benefits and Clinical Uses of NAD Injections

Proponents of NAD injections suggest a range of potential benefits, though it is crucial to emphasise that evidence supporting these claims varies considerably in quality and quantity. The most commonly cited potential applications include:

Energy and fatigue management: Given NAD+'s central role in cellular energy production, injections are marketed for combating fatigue and enhancing physical performance. Some individuals report subjective improvements in energy levels, though controlled clinical trials demonstrating objective benefits are limited. Persistent fatigue should always be assessed by a GP to investigate common reversible causes before considering unproven interventions.

Cognitive function: NAD+ is involved in neuronal health and synaptic plasticity. Preliminary research suggests potential neuroprotective effects, leading to claims about improved mental clarity, focus, and memory. However, robust clinical evidence in humans remains sparse.

Addiction and withdrawal support: Some private clinics offer NAD injections as part of addiction treatment protocols, particularly for alcohol and opioid dependence. The rationale centres on NAD+'s role in neurotransmitter regulation and cellular repair. Whilst some observational studies report reduced withdrawal symptoms, there is insufficient high-quality evidence to support this as a standard treatment. Patients should follow NICE-recommended treatments (CG115 for alcohol use disorders and CG52 for opioid detoxification) and access NHS addiction services.

Anti-ageing and metabolic health: Based on animal studies showing that NAD+ precursors may influence longevity pathways and metabolic parameters, injections are promoted for anti-ageing purposes. There is currently no evidence for lifespan extension or disease modification in humans, and translation to meaningful clinical outcomes requires further investigation.

Chronic fatigue and fibromyalgia: Anecdotal reports suggest symptom improvement in these conditions, though there is no official link established through rigorous clinical trials. Patients with these conditions should continue to follow evidence-based management strategies as outlined in NICE guidance (NG206 for ME/CFS, NG193 for chronic pain, and NICE CKS for fibromyalgia).

Importantly, NAD injections should not replace evidence-based treatments for any medical condition. Many of these applications are based on theoretical mechanisms, animal studies, or small, uncontrolled human trials rather than robust randomised controlled trials.

Safety, Side Effects and Contraindications

NAD injections are generally reported to be well tolerated, though comprehensive safety data from large-scale clinical trials is lacking. The safety profile is primarily derived from case series, observational studies, and clinical experience from private practitioners rather than formal pharmacovigilance systems.

Common side effects associated with NAD injections, particularly when administered intravenously, include:

• Injection site reactions: Pain, redness, or swelling at intramuscular injection sites

• Gastrointestinal symptoms: Nausea, cramping, or diarrhoea, especially with rapid IV infusion

• Flushing and warmth: Often described during or immediately after intravenous administration

• Chest tightness or discomfort: Typically mild and transient, but may be concerning for some patients

• Headache and dizziness: Reported occasionally, particularly with higher doses

Infusion-specific risks include thrombophlebitis, extravasation, infection, air embolism, vasovagal reactions, and changes in blood pressure or heart rate. These effects are often dose-dependent and may be mitigated by slower infusion rates or dose adjustment. Serious adverse events appear to be rare based on available reports, though the absence of systematic post-marketing surveillance means the true incidence of rare complications remains unknown.

Contraindications and precautions are not formally established due to the lack of regulatory approval, but clinical prudence suggests caution in:

• Pregnancy and breastfeeding (insufficient safety data)

• Individuals with active malignancy (theoretical concerns about enhanced cellular metabolism)

• Severe cardiovascular disease (due to reported chest symptoms)

• Known hypersensitivity to NAD or formulation components

Patient safety advice: Individuals considering NAD injections should discuss this with their GP, particularly if they have underlying health conditions or take regular medications. Administration should only be by suitably qualified clinicians in CQC-regulated settings with resuscitation facilities. Any concerning symptoms during or after administration—such as severe chest pain, difficulty breathing, or allergic reactions—warrant immediate medical attention via 999. Patients should report suspected adverse reactions to the MHRA Yellow Card Scheme (yellowcard.mhra.gov.uk or the Yellow Card app).

Evidence Base and Regulatory Status in the UK

The evidence base for NAD injections remains limited and of variable quality. Whilst basic science research has established NAD+'s crucial biochemical roles, and animal studies have demonstrated promising effects of NAD+ precursors on various health parameters, translation to clinically meaningful human outcomes is not yet well established.

Most human studies to date are small, uncontrolled, or observational in nature. Randomised controlled trials—the gold standard for evaluating therapeutic interventions—are scarce, particularly for injectable NAD+ formulations. The majority of published research focuses on oral NAD+ precursors (NR and NMN) rather than direct NAD+ injections, and even this evidence base is evolving. Systematic reviews consistently highlight the need for larger, well-designed trials with clinically relevant endpoints and longer follow-up periods.

Regulatory status in the UK is an important consideration. NAD injections are not licensed as medicines by the Medicines and Healthcare products Regulatory Agency (MHRA) for any specific therapeutic indication. They are not included in the British National Formulary (BNF) and are not prescribed within the NHS. NICE has not issued guidance on NAD injections, as they are not recognised as an evidence-based treatment for any condition.

NAD injections are primarily available through private clinics and wellness centres, often marketed as part of "IV therapy" or "nutritional medicine" services. As unlicensed medicines, NAD injections should be supplied via MHRA-licensed 'specials' manufacturers or pharmacies on a prescriber's order. The regulatory framework governing such services is complex; the MHRA regulates medicines and medical devices, whilst the Care Quality Commission (CQC) oversees healthcare service providers. Advertising of NAD injections is constrained by the MHRA Blue Guide and ASA/CAP Code, which limit medicinal claims for unlicensed products.

Patients considering NAD injections should be aware that:

• These treatments are not evidence-based medicine in the conventional sense

• Costs are entirely out-of-pocket and can be substantial

• Quality, purity, and sterility of preparations may vary between providers

• Marketing claims often exceed the available evidence

Healthcare professionals should counsel patients that whilst NAD+ biology is scientifically sound, the clinical utility of NAD injections remains unproven. Individuals seeking treatment for specific medical conditions should prioritise evidence-based interventions recommended in NICE guidance and discuss any complementary approaches with their GP or specialist.

Frequently Asked Questions