There is no single measure of better performance
A supplement can be discussed in relation to endurance, strength, fatigue or a laboratory marker. Those are separate outcomes. Before comparing bottles, decide which claim you are trying to understand and look for a study that measured it directly.
Two randomized trials illustrate why this matters. They studied different participants, formulations and durations, and do not establish that every NMN product improves exercise performance. They also do not compare NMN with an NAD+ injection service. For the underlying ingredient distinction, start with NAD+, NR and NMN explained.
A six-week trial in recreational runners
Liao and colleagues studied 48 recreationally trained runners in a randomized, double-blind, placebo-controlled trial lasting six weeks. Participants were assigned to four groups while undertaking exercise training. The investigators reported greater improvements in certain oxygen-uptake and ventilatory-threshold measures in the middle- and higher-dose groups than in the control group. [1]
VO₂max, a measure of peak aerobic capacity, did not improve. This is a finding about specified exercise-test outcomes in people who were training. It does not establish the same effect in sedentary adults, prove a faster race time, or show that NMN can replace exercise. A favorable endpoint should keep its original name rather than becoming a promise of better performance in every setting. [1]
A different trial found no improvement in several functional tests
A 2023 physiologic study randomized 30 adults aged 45 or older with overweight or obesity to a microcrystalline NMN formulation, MIB-626, or placebo for 28 days. Circulating NAD and related metabolites increased with treatment. Changes in muscle strength, muscle fatigability, aerobic capacity and stair-climbing power did not differ significantly between groups; insulin sensitivity did not change in either group. [2]
The authors also reported favorable differences in some cardiometabolic measurements and called for larger trials. That mixed result matters: a change in a blood marker can coexist with no detected improvement in a functional test. It is not a reason to erase either part of the findings. [2]
Why the studies cannot be turned into a product ranking
Putting two study headlines side by side is not a head-to-head experiment. Differences in participants, duration, formulation and training can influence what a study is able to detect. The appropriate conclusion is narrower than declaring one retail product effective or another ineffective.
When a product uses terms such as liposomal or enhanced absorption, ask whether the relevant human trial tested that finished formulation. The Renue By Science review separates its label and batch information from claims about delivery. A formulation feature and a demonstrated improvement in daily functioning are different pieces of evidence.
A useful checklist before buying
Write down the population, ingredient, comparison, duration and exact endpoint from the paper. Then compare that description with the product label and the advertised benefit. If one field does not match, keep the mismatch visible instead of filling it with an assumption.
Next, compare purchase commitments rather than promising yourself a result by the next renewal. Use the cost worksheet for quantity, shipping and recurring charges. Bring questions about suitability and symptoms to a qualified clinician. This discussion is a close reading of two illustrative trials, not a treatment recommendation or an exhaustive review.