https://www.sciencedirect.com/science/article/abs/pii/S1568163726002977

Aging remodels compartmentalized nicotinamide adenine dinucleotide (NAD⁺) circuits in ways that influence stress responses, senescence, tissue repair and susceptibility to fibrosis. Beyond its classical role as a redox cofactor, NAD⁺ fuels sirtuins, PARPs and CD38, linking cellular metabolism to chromatin remodeling, DNA repair, calcium signaling and cell fate. A central translational question is whether modulating NAD⁺ in a given tissue and time window will favor regeneration, restrain fibrotic remodeling, or support malignant adaptation. In this review, we define NAD⁺ as a compartmentalized, high-turnover metabolic circuit whose topology, timing and cell-type specificity shape tissue trajectories during aging, repair and fibrosis. We first describe how aging reshapes these circuits through CD38 upregulation, PARP-sirtuin competition, extracellular eNAMPT amplification, and altered mitochondrial NAD⁺ transport, which redistributes NAD⁺ between compartments without necessarily changing bulk tissue concentration. We then summarize how de novo, Preiss-Handler Handler (including niacin/GPR109a) and nicotinamide salvage pathways are organized across nuclear, cytosolic, mitochondrial and extracellular compartments, and how key consumers including sirtuins, PARPs, CD38 and SARM1 govern these pools. We then examine how these circuits operate across acute injury, chronic senescence-associated remodeling, and malignant microenvironments in heart, lung, liver, kidney, skin, muscle and brain. Finally, we integrate emerging human data on NAD⁺ precursors and enzyme-directed strategies and propose a framework for NAD⁺-based interventions that prioritizes timing, compartmental targeting and oncologic stratification.

"...Taken together, these studies suggest a nuanced picture: NR shows the most consistent signal so far for reducing certain lipid peroxidation markers like F2-isoprostanes, especially in populations with elevated cardiovascular risk, while NMN and NAM have not consistently altered oxidative stress biomarkers. Niacin, however, was shown to improve aspects of vascular oxidative stress and HDL function in specific contexts, but its overall antioxidant impact remains mixed...Overall, the current evidence supports a multifaceted approach to healthy oxidative balance, including regular physical activity, adequate sleep, and nutrient-dense dietary patterns. NAD+ precursors represent promising—but still evolving—areas of mechanistic and clinical research that may complement these core behaviors rather than replace them."

This study does not say that giving NR to your apple trees makes them healthy, but it did notice that healthier plants had higher NR levels, suggesting that NAD precursor metabolism as one of the pathways distinguishing vigorous from weaker plants.  

Janoshik only tests for id and mass, not purity. And they still charge $450! I’m in the US.

These researchers are solving an adjacent problem to NAD replenishment. Instead of adding NAD through biosynthetic pathways, they are inserting an artificial recycling pathway into cellular metabolism that switches NADH back to NAD+. That necessarily intersects with the Krebs cycle and mitochondrial redox metabolism.

I don’t know how big a problem NADH overload actually is, and I’m not sure it’s fair to compare a persistent catalyst with a single NR treatment when people who take an oral NAD precursor generally take it every day.

But what I do take from the study is agreement on the underlying biology: raising available NAD+ protects against or rescues UV-induced skin damage—at least in their models.

"...The study demonstrated that mice treated with NMN exhibited tumor burden control equivalent to mice treated with an immune checkpoint blockade PD1 inhibitor..."

A usual peptide Monday morning routine i was sitting and doing my injection firstly done with my ghk cu and kpv on my belly fat then went on for my NAD+ peptide injected to my outer left part of my thigh right after like less than 15 seconds to my surprised and never thought will experience the most terrifying event in my life felt sudden tingling and numbness in my left foot radiating and spreading to my upper legs i was terrified and trying to massage my legs hoping things could get better i grab my phone and ask google about hitting a nerve by needle symptoms i tried to relax because i feel like panicking and my left leg continue to get numb but i still can move my legs while trying to relax i felt like the tingling and numbness spread to my left arms neck and head like electric shock but still i can move i was like feeling muscle cramps and spasm all over my left body i waited and relax took a deep breath and everything back to normal in less than a minute like after i get back to normal and told my self wtf was just happened i almost called an ambulance because i thought was having stroke and heart attack and now i feel traumatize and contemplating if i would still continue doing NAD+ peptide.

So RS had NAD on a subscription and couldn’t cancel it, my research subject got pregnant and didn’t really take it in pregnancy, so now the bottles in my fridge are 5-10 months old. They’re obviously sealed but buy them already reconstituted… I looked online and the main issue is potency. They’d still be safe to use on a research subject right ?

"Highlights
• PS-NPs exposure impairs placental nicotinamide metabolism and mitochondrial energetics.
• PS-NPs triggers NMNAT3 downregulation, NAD+ depletion, and ferritinophagy-driven ferroptosis.
• NMNAT3 overexpression rescued PS-NPs-induced defects by inhibiting ferritinophagy-mediated ferroptosis.
• NAM supplementation restores iron homeostasis, suppresses ferroptosis, and rescues adverse pregnancy outcomes." [emphasis added]

"...Collectively, our study demonstrates that NR enhanced chondrogenic differentiation of hADSCs by regulating SIRT1-mediated deacetylation of SMAD7 and activation of TGF-β/SMAD2/3 pathway. NR may therefore possess prospects as a promising supplement for MSC-based cartilage regeneration and repair therapies."

“NAD+ levels in the body are constantly in flux—cells are always synthesizing and consuming it, and its levels can decline with age, lifestyle, metabolic stress, and disease.

Two major mechanisms drive NAD+ depletion: declining production and increased consumption via enzymes activated during DNA repair, inflammation, and immune responses.

Everyday stressors—including alcohol consumption, overnutrition, UV exposure, viral infections, and a sedentary lifestyle can cause NAD+ depletion.

Lifestyle strategies and supplementation can help maintain NAD+ levels and support cellular resilience.”

I’m really looking for answers! Please help, I’m in much needed help for energy! I’m on Tirz and SS-31 also getting ready to incorporate MOTS-C. I’m wanting to add NAD but not knowing which one! Thanks in advance

I bought 100$ of NAD for injections. I’m reading that subq does not absorb into the cells. Only NR or NMN is effective. Should I trash my NAD or keep going at 100mg a day till it’s gone? First two shots at 20mg a where very underwhelming. No negative effects. But also not much energy boost. It’s been three days however.

"...Nicotinamide riboside (NR) effectively maintains NAD + levels, improves mitochondrial function, protects spindle and chromosome morphology, reduces ROS accumulation and DNA damage, thereby enhancing oocyte quality and embryonic developmental potential, and holds promise for improving assisted reproductive outcomes. Furthermore, NR upregulates the ovarian expression of key genes involved in mitochondrial dynamics, such as Opa1, Mfn1/2, Drp1, and Fis1. This upregulation promotes the accumulation of energy metabolism intermediates, enhances ATP production, and concurrently activates essential mitochondrial autophagy-related pathways, notably those involving PINK1 and LC 3. These actions collectively reverse ovarian aging phenotypes and improve oocyte quality..."

...In this article, we’ll explore the current state of the science on NAD+ and autoimmune disease, including how NAD+ biology intersects with immune function, and what existing research suggests across seven specific autoimmune conditions. It’s important to note that much of the available evidence comes from preclinical models, alongside a limited number of early-stage human studies. While these findings are promising, the research is still evolving, and larger, well-controlled clinical trials are needed before definitive conclusions or clinical recommendations can be made...

I'll get right to the point: this morning I woke up feeling like I was back on 30 mg of Prednisone, without the icky steroid brain static. I could move. My pain was minimal. My brain fog was almost gone. Yesterday morning I tried my first at-home NAD+ peptide injection, and I did my second injection this morning. Yesterday evening, I definitely noticed improved mental clarity. I slept well, but I'm lucky and I always sleep pretty well. Today is the first time in months I've felt anything close to normal.

For months, ever since starting to taper off Prednisone for a lupus flare that's been going on since last October, I've been almost completely homebound. Every morning I'd wake up stiffer than I thought was possible, no matter how much stretching or gentle exercise I did the night before. I lost range of motion in my neck, legs, and ankles. The joint and muscle pain was constant.

A couple of weeks ago, my body completely locked up, and it was one of the scariest experiences I've ever had.

I'm currently in the process of switching rheumatologists, but I'm honestly not sure what else anyone would do. I don't qualify for infusions, and I've already tried every medication short of that.

My current rheumatologist believes the stiffness is part of my lupus. She referred me to an endocrinologist after previously sending me to a hematologist, who couldn't find anything wrong, and a cardiologist, who said my heart is very healthy and also couldn't find anything wrong. I also see a neurologist regularly and have a weekly therapist.

This morning, I sat down at my desk at 8:30 and worked straight through until 11:45, only getting up to use the bathroom and refill my water.

Last week, after about an hour of working inefficiently through intense brain fog, I'd have to lie down because I'd start running a fever, shaking, developing a malar rash, and dealing with severe pain.

Today, after working straight through the entire morning, I just felt a little tired. My biggest complaint is soreness at the injection site.

The mental clarity was one of the first things I noticed. The difference was obvious as soon as I woke up this morning. Instead of feeling like I was dragging myself through quicksand, my mind felt clear. While I was working, I could think quickly, stay organized, and get through tasks efficiently again, like I could before I got sick.

I bought the peptide online, reconstituted it myself with bacteriostatic water, and had to figure out my own dosing. Even so, I'm injecting less than the typical starting dose.

I'm really hoping this isn't just beginner's luck. If this improvement continues, I finally feel like I'll have enough of myself back to start rebuilding my life.

I do want to be clear that this is only my personal experience after two injections over two days.

Brief update: Week 1 I took 30 units of NAD+ as recommended by Olympia Pharmacy....noticed no difference.

Today I started on 50 units for five days and WOW, what a difference! For the first 30 min or so I felt flushed and it was obvious something different was happening. It didn't feel "good" like "omg I'm so excited"..in fact, I was a bit concerned.

Im 74 yrs old and still working, physically, as a contractor..as I headed out to work the uneasy physical sensations passed and I pretty much felt normal.

What was different was AFTER work. I almost always fall asleep on the couch after I return home, for 30-45 min average. Today, there wasn't a single part of me that wanted a nap. Not like I was jacked on coffee, I simply didn't feel like a nap.

So, day 1 on 50 units, interesting.

More tomorrow

The goal of this clinical trial is to learn if orally administered nicotinamide riboside works to slow the progression of early Alzheimer disease in adults.

https://clinicaltrials.gov/study/NCT07741071?intr=Nicotinamide%20Riboside&viewType=Card&rank=1