Nicotinamide Mononucleotide (NMN) is a precursor to nicotinamide adenine dinucleotide (NAD+), a molecule essential for cellular metabolism and energy production. There is emerging preclinical scientific evidence suggesting that NMN may help reduce some side effects of chemotherapy, primarily through its role in supporting cellular repair and mitigating oxidative stress. In animal studies, NMN supplementation has shown promise in ameliorating chemotherapy-induced hematopoietic (blood cell-forming) toxicity and protecting against organ damage, such as in the heart or nervous system, which can be compromised during chemotherapy. For example, a 2020 study in mice demonstrated that NMN could reduce doxorubicin-induced cardiotoxicity by enhancing NAD+ biosynthesis and improving mitochondrial function.

However, human clinical trials are very limited. Most current data come from animal models or in vitro studies, which may not fully translate to human patients. Some phase I and II clinical trials are underway to investigate NMN’s safety and potential to support chemotherapy patients, but as of mid-2024, no large-scale human evidence conclusively supports its widespread use for this purpose. Therefore, while there is a scientific rationale and early-stage evidence, the overall strength of evidence supporting NMN's use to reduce chemotherapy side effects remains relatively low (rated 2 out of 5), pending results from more robust human studies.