Absorption and Tolerability of Injectable Administration of Niagen®+, as Compared to NAD+

Inclusion Criteria:

• Provision of signed and dated informed consent form

• Stated willingness and demonstrated ability to comply with all study procedures, aswell as availability for the duration of the study

• Lives within 100 miles of the NRI study site

• Any gender, aged 40-65, inclusive

• Good general health as evidenced by medical history

• BMI 25-34.9 kg/m2

• Sedentary behavior (defined as <20 minutes per day or 100 minutes per week ofmoderate to vigorous exercise)

• Demonstrated fatigue (Fatigue Assessment Scale) defined as a below-average score

• For females of reproductive potential: use of highly effective contraception for atleast 1 month prior to screening and agreement to use such a method during studyparticipation and for an additional month after the end of the study

• Agreement to adhere to Lifestyle Considerations throughout study duration

Exclusion Criteria:

• Current diagnosis of any seizure disorder, diabetes or insulin resistance, anykidney or liver disorder, heart disease, anemia, cancer, or Parkinson's disease

• ANY chronic illness (pre-disease state acceptable)

• Out of range phosphate levels at baseline

• BMI less than 25 or greater than or equal to 35

• Pregnancy, trying to conceive, or breastfeeding

• Known allergic reactions to any components of the intervention or related compounds,including any form of B3

• Positive COVID-19 test within 30 days of the study period

• Recent dramatic weight changes (10% change in body weight in the last 6 months)

• Existing usage of a NAD+ or NAD precursor supplement in any form (oral, nasal,patch, or injection/IV administration), including a B-complex supplement, within 60days of the study, not including multivitamins.

• Introducing a new medication, supplement, investigational drug, or otherintervention (including lifestyle changes) within 60 days of the start of the study.