Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of NAD+ and P21 — mechanism, side effects, legal status, and pricing.
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme present in all living cells, not a peptide. It is classified here alongside peptides for user convenience in the anti-aging / metabolic category. NAD+ plays a central role in cellular energy metabolism and redox reactions and is studied for its involvement in mitochondrial function, DNA-damage signaling via sirtuins and PARPs, and age-associated metabolic decline. IV NAD+ is not FDA-approved for any clinical indication; it is administered off-label through compounding pharmacies and functional-medicine clinics with limited rigorous outcome data.
P21 (also P021) is a small peptidergic compound — the tetrapeptide core Asp-Gly-Gly-Leu with an N-terminal acetyl and a C-terminal adamantylated glycine amide (Ac-DGGL(A)G-NH2) — derived from an active region (residues ~148–151) of human ciliary neurotrophic factor (CNTF). It was designed and characterized in the Khalid Iqbal laboratory at the New York State Institute for Basic Research in Developmental Disabilities (NYS IBR). It is an experimental, preclinical compound — NOT FDA-approved and NOT tested in humans in published trials. Distinct from the cyclin-dependent kinase inhibitor protein p21/CDKN1A/WAF1 (a completely different gene product; the two share only the name).
NAD+
P21
Category
Legal Status
Mechanism
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
NAD+
P21
COA corpus from Disclosed Labs — independently tested batches only.
NAD+
146
COAs
99.4%
Avg purity
15
Labs
P21
2
COAs
99.1%
Avg purity
1
Labs
The strongest human evidence for raising circulating NAD+ comes from oral-precursor trials. A randomized, double-blind, placebo-controlled study of nicotinamide riboside combined with pterostilbene (NRPT) showed sustained dose-dependent increases in whole-blood NAD+ over 8 weeks in healthy adults (Dellinger et al., npj Aging and Mechanisms of Disease, 2017). A Yoshino/Baur/Imai review summarizes the biology and emerging therapeutic potential of NR and NMN, including preclinical healthspan data in aged mice (Cell Metabolism, 2018). Direct IV NAD+ has only small pilot pharmacokinetic data: Grant et al. infused 750 mg over 6 hours in 8 healthy men and documented altered plasma and urine NAD+ metabolome without clinical-outcome endpoints (Frontiers in Aging Neuroscience, 2019). No adequately powered RCTs support IV or SubQ NAD+ for anti-aging, cognition, addiction, or Parkinson's disease; clinic marketing claims outrun the published outcome evidence.
Key references
Evidence is preclinical (rodent) only. Key publication: Kazim, Blanchard, Dai, Tung, LaFerla, Iqbal & Iqbal, Neurobiology of Disease 2014 (PMID 25046994) reported that chronic oral P021 rescued cognition, boosted dentate-gyrus neurogenesis, and reduced tau hyperphosphorylation in 3xTg-AD mice. Additional preclinical papers from the Iqbal group (and collaborators) have shown dendritic/synaptic rescue in AD and aging rodent models (e.g., Kazim et al., Alzheimer's Res Ther 2017). No Phase 1/2/3 human trials have been published; no human safety or pharmacokinetic data exist. Grey-market vendor material is unvalidated — purity, identity, and dosing are not verifiable.
Key references
NAD+ (Metabolic) and P21 (Cognitive) are in different categories and target different biological pathways. This is a common pattern in multi-compound research protocols. Researchers should monitor the biomarkers from both profiles and watch for interactions listed in each compound’s contraindications. Consult a licensed healthcare provider before combining any research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Disclosed Labs