The goal of this clinical trial is to assess the absorption, safety, and efficacy of an NAD+ supplement in healthy adults. The main question it aims to answer is: What is the change in NAD+ levels in whole blood from baseline to day 56 between the NAD+ supplement and placebo? Researchers will compare the NAD+ supplement to placebo to evaluate its absorption, safety, and efficacy. Participants will be asked to:

• Complete questionnaires
• Provide blood samples
• Consume either the NAD+ supplement or a placebo for 55 days
• Have their endothelial function evaluated

Inclusion Criteria:

1. Males and females between 40 and 65 years of age, inclusive, at screening

2. Body Mass Index (BMI) between 18.5 and 29.9 kg/m2

3. Females not of child-bearing potential, defined as those who have undergone a sterilization procedure (e.g. hysterectomy, bilateral oophorectomy, bilateral tubal ligation, complete endometrial ablation) or have been post-menopausal for at least 1 year prior to screening Or, Individuals of child-bearing potential must have a negative baseline urine pregnancy test and agree to use a medically approved method of birth control for the duration of the study. All hormonal birth control must have been in use for a minimum of three months. Acceptable methods of birth control include:

   • Hormonal contraceptives including oral contraceptives, hormone birth control patch (Ortho Evra), vaginal contraceptive ring (NuvaRing), injectable contraceptives (Depo-Provera, Lunelle), or hormone implant (Norplant System)
   • Double-barrier method
   • Intrauterine devices
   • Non-heterosexual lifestyle and agrees to use contraception if planning on changing to heterosexual partner(s)
   • Vasectomy of partner at least 6 months prior to screening
   • Abstinence and agrees to use contraception if planning on becoming sexually active during the study

4. Willingness to complete questionnaires and diaries associated with the study and to complete all visits

5. Agrees to maintain current lifestyle habits (physical activity, medications, supplements, and sleep) as much as possible throughout the study

6. Agrees to follow the specified low NAD-precursor diet during the run-in period and throughout the study

7. Agrees to avoid caffeine (e.g., tea, coffee, energy drinks) for 12 hours (h) prior to post-screening in-clinic study visits

8. Agrees to avoid alcohol consumption and vigorous physical activity for 24 h prior to post-screening in-clinic study visits

9. Provided voluntary, written, informed consent to participate in the study

10. Healthy as determined by medical history and laboratory results as assessed by the Qualified Investigator (QI)

Exclusion Criteria:

1. Individuals who are pregnant, breast feeding, or planning to become pregnant during the study
2. Allergy, sensitivity, intolerance, or dietary restriction preventing consumption of investigational product (test material's active or inactive ingredient) or placebo ingredients
3. Unstable metabolic disease or chronic diseases as assessed by the QI
4. Current or history of any significant diseases of the gastrointestinal tract as assessed by the QI
5. Unstable hypertension. Treatment on a stable dose of medication for at least 3 months will be considered by the QI (See Section 1)
6. Significant cardiovascular event in the past 6 months. Participants with no significant cardiovascular event on stable medication may be included after assessment by the QI on a case-by-case basis
7. History of or current diagnosis with kidney and/or liver diseases as assessed by the QI on a case-by-case basis, with the exception of history of kidney stones in participants who are symptom free for 6 months
8. Self-reported confirmation of current or pre-existing thyroid condition. Treatment on a stable dose of medication for at least 3 months will be considered by the QI
9. Major surgery in the past 3 months or individuals who have planned surgery during the course of the study. Participants with minor surgery will be considered on a case-by-case basis by the QI
10. Cancer, except skin basal cell carcinoma completely excised with no chemotherapy or radiation with a follow up that is negative. Volunteers with cancer in full remission for more than five years after diagnosis are acceptable
11. Individuals with an autoimmune disease or are immune compromised as assessed by the QI
12. Self-reported confirmation of a human immunodeficiency virus (HIV)-, Hepatitis B- and/or C-positive diagnosis as assessed by the QI
13. Self-reported confirmation of blood/bleeding disorders as assessed by the QI
14. Use of medical cannabinoid products
15. Chronic use of cannabinoid products (>2 times/week). Occasional users will be required to washout and abstain for the duration of the study period
16. Regular use of tobacco or nicotine products in the past six months, as assessed by the QI. Occasional users will be required to washout and abstain for the duration of the study period
17. Alcohol intake average of >2 standard drinks per day as assessed by the QI
18. Alcohol or drug abuse within the last 12 months
19. Current use of prescribed and/or over-the-counter (OTC) medications, supplements, and/or consumption of food/drinks that may impact the efficacy and/or safety of the investigational product (Sections 7.3.1 and 7.3.2)
20. Clinically significant abnormal laboratory results at screening as assessed by the QI
21. Blood donation 30 days prior to baseline, during the study, or a planned donation within 30 days of the last study visit
22. Participation in other clinical research studies 30 days prior to baseline, as assessed by the QI
23. Individuals who are cognitively impaired and/or who are unable to give informed consent
24. Any other condition or lifestyle factor, that, in the opinion of the QI, may adversely affect the participant's ability to complete the study or its measures or pose significant risk to the participant