NAD+ benefits: what the evidence can—and cannot—tell us

Start with what was actually measured

A biomarker is a measurable feature, such as a substance in blood. A patient outcome is something that matters to a person’s health or function. Changes in a marker can be scientifically interesting without proving that someone sleeps better, remembers more, or lives longer.

When reading a claim, write down the exact result the study measured. Then compare it with the benefit in the advertisement. If the study tracked metabolites and the advertisement promises better daily energy, there is a step in the reasoning that still needs evidence.

The 2019 human IV pilot

Grant and colleagues studied changes in plasma and urine NAD-related metabolites during and after a six-hour NAD+ infusion. This is direct human evidence about that research protocol, but its small scale and metabolic focus limit what it establishes.

It is not a trial showing that a particular telehealth brand’s home injections improve longevity, nor does it establish a schedule for self-administration. We link the original paper so readers can inspect its methods and limitations. Do not turn a research infusion protocol into personal dosing instructions.

Newer tolerability evidence answers a narrower question

The 2026 Reyna publication is a retrospective pilot comparing IV NAD+ and IV nicotinamide riboside in a real-world setting. Its focus includes tolerability and infusion-related observations. A retrospective comparison is useful context, but it does not establish long-term benefits or the effectiveness of a different home formulation.

The PubMed record identifies the design. Before treating a newer paper as a breakthrough, look at how participants were selected, what was compared, how symptoms were recorded, and whether the outcome matches the claim you care about.

Read surveys and testimonials differently

Customer stories can describe experiences, but they cannot isolate the effect of treatment. Respondents may also change exercise, sleep, diet, or other medicines. People who do not improve may stop participating. A large survey still needs its design considered carefully.

Our AgelessRx review discusses this because its product materials feature customer-reported results. We do not treat a provider’s survey as a controlled trial, invent a success percentage, or assign clinical scores from testimonials.

Turn uncertainty into a better appointment

Ask the clinician which evidence is relevant to your actual prescription and your concern. Agree on what you hope will change, how you will assess it, and when to revisit the decision. Include unwanted effects and cost in that review.

It is reasonable to decide that the uncertainty, route, or ongoing expense does not fit your priorities. It is also reasonable to request more information before making a decision. Use the appointment checklist and cost guide to make the discussion specific.

Read the evidence for your specific goal.

Explore the separate evidence for energy and fatigue, weight loss, brain and memory, skin and hair, and aging. Our 2026 research reading guide includes newer human blood-level and cognitive studies. Before-and-after claims and NAD testing need their own evidence checks.