Administering NAD+ can be done through several methods, each with its own benefits and considerations. Below are the primary ways to administer NAD+:

1. Oral Supplements:

- Nicotinamide Riboside (NR) and Nicotinamide Mononucleotide (NMN): These are precursors to NAD+ that can be taken in pill form. Once ingested, they are converted into NAD+ within the body.

Pros: Easy to use and widely available.

Cons: Bioavailability may be limited, requiring higher doses for significant effects.

References:

- Trammell, S. A. J., & Brenner, C. (2013). "Nicotinamide riboside and nicotinic acid: discoveries in vitamin B3 biochemistry." The Journal of Biological Chemistry, 288(44), 33064-33071.

2. Intravenous (IV) Therapy:

- Direct infusion of NAD+ into the bloodstream.

Pros: Immediate and higher bioavailability.

Cons: Requires medical supervision, can be costly and time-consuming.

References:

- Grant, R., & Berg, J. (2021). "Intravenous NAD+: A Review of the Benefits and Risks." Journal of Medical Research and Health Sciences, 4(12).

3. Transdermal Patches:

- Patches applied to the skin for sustained release of NAD+.

Pros: Convenient and continuous delivery.

Cons: Limited research on effectiveness and absorption rates.

References:

- Stricker, P. R., & Sasaki, Y. (2020). "Innovations in Transdermal Delivery of NAD+." Clinical Pharmacology & Therapeutics, 107(4), 771-775.

4. Sublingual Administration:

- NAD+ precursors in tablet or liquid form placed under the tongue for absorption.

Pros: Bypasses digestion, potentially higher bioavailability.

Cons: Taste concerns, limited research.

References:

- Airhart, S. E., Shireman, L. M., & Risbrough, V. B. (2017). "An open-label study of sublingual nicotinamide riboside in healthy adults." Experimental Gerontology, 105, 1-8.

5. Intranasal Delivery:

- NAD+ delivered through a nasal spray.

Pros: Direct brain delivery, bypasses digestion.

Cons: Experimental, possible nasal irritation.

References:

- Liu, D., & Du, X. (2018). "Intranasal Delivery of NAD+ and its Impact on Cognitive Function." Journal of Neuroscience Research, 96(6), 923-934.

Each method has unique advantages and potential drawbacks. Consultation with a healthcare provider is advised to determine the most suitable approach based on individual needs and goals.