The NAD⁺ crisis your doctor hasn't told you about...

...and the four-pathway solution that changes everything.

You’re too young to feel this tired.

Remember when you could stay up until 2 AM and still crush it the next day? When hangovers lasted hours, not days? When you could stay focused without that afternoon espresso?

The resilience and energy of youth comes from NAD⁺.

By age 50, you have half the NAD⁺ you had at 20. As you celebrate more birthdays, that decline continues further.¹

You don't have to accept this as "normal aging" when you look at it as a solvable problem.

What is NAD⁺ and why should you care?

Think of NAD⁺ (nicotinamide adenine dinucleotide) as your cellular fuel and repair crew rolled into one.

Every cell in your body uses NAD⁺ to:

  • Turn food into energy. Without it, your mitochondria can't make ATP.Β²
  • Repair DNA damage that happens 70,000 times per day.Β³
  • Activate longevity genes called sirtuins that keep cells strong.⁴
  • Clean out cellular garbage like damaged proteins and dying mitochondria.⁡
Dr. Rebecca Crews, Research Director

When NAD⁺ is high, these processes hum along. You feel energetic, recover quickly, think clearly.

When NAD⁺ drops? Everything slows down. Energy tanks. Recovery drags. Brain fog sets in. You age faster.

  • The good news: We can restore NAD⁺ levels. But most people are doing it wrong, if they’re doing it at all.

How your cells actually use NAD+:

Imagine your cells as your smartphone's power system.

  • ATP is the actual power running your apps.
  • NAD+ is the battery management system that delivers power where needed.
  • Mitochondria are the battery cells storing and releasing energy.
  • DNA repair is like critical system updates that need battery power to install.
  • Sirtuins are the power-saving modes that optimize battery life.
  • CD38 is like having brightness maxed out with 20 apps running in the background, draining your battery faster than you can charge it.

The hidden cost of low NAD⁺: it's not just energy.

Beyond feeling tired, low NAD⁺ creates a cascade of cellular dysfunction:

The Brain Tax

The Recovery Debt

The Metabolic Slowdown

The Aging Accelerator

Your brain uses ~20% of your body’s resting energy,6 and neurons depend on NAD⁺ to fuel the ATP that keeps them firing. As NAD⁺ falls with age or stress, your brain’s energy efficiency declines, contributing to mental fatigue and brain fog.

The single-supplement trap.

Why Just Taking NMN Isn't Enough.

Here's what most NAD⁺ supplements don't tell you:

Taking NMN or NR alone is like filling a bucket with holes in it. Sure, you're adding NAD⁺ to your system by taking a precursor, but you're not addressing:

  • The enzymes (like CD38) breaking down your NAD⁺ faster than you can make it .1⁰
  • The inflammation driving those enzymes higher.ΒΉΒΉ
  • The inefficient mitochondria wasting what NAD⁺ you do have.ΒΉΒ²
  • The cellular damage creating constant NAD⁺ demand.ΒΉΒ³

This is why people take NMN for a month, feel great, then plateau. They're fighting a losing battle.

More NMN alone won't solve the problem. The right answer is a smarter strategy.

The four pathways:

a complete NAD+ restoration system.

After analyzing hundreds of studies, we've identified four critical pathways that work together to restore and maintain youthful NAD⁺ levels.

NAD⁺ boosters like NMN and NR are only the beginning.

After years of analyzing the research, we've aligned with a systems-level approach to address four main pathways to support healthy NAD+ levels throughout the entire body. This systems-level approach is described elegantly by Nichola Conlon and Dianne Ford in a recent study on NAD+ restoration.

Every Renue By Science formula helps you maximize NAD+ through one of these pathways.

  • Boost
  • Protect
  • Optimize
  • Regenerate
BOOST

Build your NAD+ reserves.

  • The Problem: Your body makes NAD⁺ through multiple routes, but they all decline with age. The main recycling pathway, using an enzyme called NAMPT, gets overwhelmed.¹⁴
  • The Solution: Supply multiple NAD⁺ precursors that use different pathways:
  • NMN: Uses the Salvage pathway, most direct route.
  • NR: Uses the NR Kinase pathway, the backup route.
  • Trigonelline: Uses the Preiss-Handler pathway, the third option.
  • Direct NAD⁺: Gets broken down and rebuilt.³⁷

Why This Works: Different tissues prefer different routes.¹⁡ Your liver likes one pathway, your muscles another. By providing multiple options, cells can choose the fastest route available, no bottlenecks.

Research Shows: Steady NAD+ levels throughout the day, supporting consistent energy and cellular function.15

Human signals:

  • NMN (metabolism & muscle): 250 mg/day for 10 weeks improved muscle insulin sensitivity and increased circulating NAD⁺-related metabolites in postmenopausal adults with impaired glucose regulation.¹⁢
  • NMN (capacity & blood NAD⁺): 250 mg/day for 12 weeks increased whole-blood NAD⁺ and produced small gains in gait speed and grip strength in healthy older men.¹⁷
  • NMN (vascular structure): 12 weeks increased NAD⁺ metabolites and improved arterial stiffness in participants with higher baseline stiffness.¹⁸
  • NR (blood & cardiovascular): 1,000 mg/day elevated the blood NAD⁺ metabolome and showed exploratory reductions in systolic BP/aortic stiffness in older adults.¹⁹
  • Trigonelline (muscle function): translational work links it to NAD metabolism and age-related muscle function; early human-relevant signals.²⁰
Protect

Stop the NAD⁺ drain.

  • The Problem: Two enzymes are destroying your NAD⁺ faster than you can make it:
  • CD38 increases dramatically with age and inflammation, using up massive amounts of NAD⁺.Β²ΒΉ
  • PARPs consume NAD⁺ trying to repair constant DNA damage.Β²Β²

It's like having a Ferrari with a fuel leak. It doesn't matter how much gas you add, you're going to slow down and stall out.

  • Quercetin: Directly inhibits CD38 in in-vitro studies, preserving NAD⁺.Β²Β³
  • Fisetin: Prunes senescent cells that drive inflammation.²⁴
  • Apigenin: Documented CD38 inhibitor in cell and mouse studies.Β²Β³
  • Hesperidin: Soothes inflammatory signals that can trigger CD38.²⁡

Why This Works: Studies show quercetin and apigenin can downshift CD38 activity.²³ That means the NAD⁺ you make actually stays available for useful work.

Research Shows: Supplements that "stopped working" suddenly start to work again.Β 

Research highlights:

  • CD38 inhibition (metabolic restoration): Potent CD38 inhibitor ameliorated age-related metabolic dysfunction by reversing tissue NAD⁺ decline in aged mice, improving glucose tolerance and physical activity while reducing inflammation markers.Β²ΒΉ
  • Quercetin & Apigenin (NAD⁺ preservation): Flavonoids demonstrated CD38 inhibition in diabetic mouse models, increasing cellular NAD⁺ levels by up to 50% and improving insulin sensitivity and metabolic syndrome parameters.Β²Β³
  • Fisetin (senotherapeutic action): Extended healthspan and lifespan in mice by selectively clearing senescent cells, reducing senescence markers by 25-35% and decreasing inflammatory factors that drive NAD⁺ depletion.²⁴
  • Hesperidin (inflammation reduction): Meta-analysis of randomized controlled human trials showed significant reductions in CRP, TNF-Ξ±, and IL-6 inflammatory markers that trigger CD38 expression and NAD⁺ consumption.²⁡
Optimize

Use NAD⁺ more efficiently.

  • The Problem: Inefficient mitochondria waste NAD⁺. It's like driving with the parking brake on: you burn more fuel for less output, burning out gears in the process.
  • The Solution: Compounds that improve mitochondrial efficiency and activate AMPK:
  • Resveratrol: Activates SIRT1 and mitochondrial biogenesis.²⁢
  • Berberine: Powerful AMPK activator, protects glucose handling.²⁷
  • EGCG: Triggers mitophagy, the removal of damaged mitochondria.²⁸
  • CoQ10: Supports electron transport chain efficiency.²⁹, 36
  • CaAKG: Fuels the Krebs cycle, improves NAD⁺/NADH ratio with demonstrated benefits in mouse models.³⁰

Why This Works: When mitochondria run clean, they need less NAD⁺ to make the same amount of energy. AMPK activation also triggers the production of new, more efficient mitochondria.³¹

Research Shows: Better endurance, faster recovery, improved metabolic markers.

Human signals:

  • Resveratrol (metabolic mimicry): 30 days of supplementation in obese humans produced calorie restriction-like effects, improving energy metabolism, reducing inflammation, and increasing mitochondrial efficiency markers.²⁢
  • Berberine (glucose & AMPK): Systematic review and meta-analysis showed significant improvements in type 2 diabetes markers through AMPK activation, with effects comparable to metformin.²⁷
  • EGCG (mitochondrial cleanup): Promoted autophagy-dependent survival by balancing mTOR-AMPK pathways, clearing damaged mitochondria and improving cellular energy efficiency.²⁸
  • CoQ10 (vascular & mitochondrial): Chronic supplementation with mitochondrial-targeted antioxidant improved vascular function and reduced oxidative stress in healthy older adults.²⁹
  • CaAKG (longevity & compression): Extended lifespan by 12% and compressed morbidity in aging mice, improving NAD⁺/NADH ratio and mitochondrial function.³⁰
Regenerate

Nighttime cellular cleanup.

  • The Problem: Damaged cellular parts create constant NAD⁺ demand for repairs. It's like trying to heat a house with broken windows.
  • The Solution: Activate autophagy, cellular recycling, during sleep:
  • Spermidine: Triggers autophagy and mitophagy.Β³Β²
  • Quality sleep supported by Restore PM: When cellular cleanup actually happens.Β³Β³, 35

Why This Works: Removing damaged proteins and mitochondria at night means less NAD⁺ needed for emergency repairs during the day. Clean cells are efficient cells.

Research Shows: Waking up refreshed instead of briefly just "less tired."

Research highlights:

  • Spermidine (cardioprotection & longevity): Natural polyamine extended lifespan in mice while providing cardioprotection, increasing autophagy markers by 20-30% and improving mitochondrialfunction.Β³Β²
  • Spermidine (cognitive preservation): Randomized controlled trial in older adults at risk for dementia showed improved memory performance after 3 months of supplementation.Β³Β³
  • Sleep (metabolite clearance): Groundbreaking research showed sleep drives 60% increase in interstitial space, allowing cerebrospinal fluid to flush metabolic waste including proteins that accumulate with NAD⁺ dysfunction.³⁡
  • Autophagy timing (circadian optimization): Peak autophagy occurs during sleep phases when NAD⁺ regeneration is highest, making nighttime the optimal window for cellular cleanup and repair. Β³Β²,³⁡

Why all four pathways matter.

Each pathway addresses a different bottleneck in NAD+ metabolism, and they work synergistically:

BOOST provides NAD+ precursors through multiple biosynthetic routes: salvage, Preiss-Handler, and NR kinase pathways. This increases substrate availability for NAD+ production.¹⁡

PROTECT inhibits CD38 and reduces inflammation-driven NAD+ consumption. CD38 activity can consume 100x more NAD+ than other enzymes, so blocking it preserves your NAD+ pool.³⁸

OPTIMIZE improves mitochondrial efficiency through SIRT1 activation and AMPK signaling. More efficient mitochondria require less NAD+ to produce the same amount of ATP.²⁢, ³¹

REGENERATE activates autophagy and cellular cleanup during sleep, reducing the accumulated damage that creates NAD+ demand for repairs.³², ³⁡

When combined, these pathways create a positive feedback loop:

  • Multiple precursors prevent pathway saturation.
  • CD38 inhibition preserves what you produce.
  • Efficient mitochondria reduce NAD+ consumption.
  • Overnight cleanup minimizes repair demands.

The result: NAD+ levels rise and stabilize rather than experiencing the typical single-supplement plateau. Research shows multi-pathway interventions achieve better outcomes than single precursor supplementation alone.

Making It Real.

Understanding the four pathways changes how you think about energy and aging. You now see why that afternoon crash happens, why recovery takes longer than it used to, and why some supplements work initially then fade.

More importantly, you understand there's a systematic way forward.

Some people start with just one pathway, usually BOOST for quick energy improvements or PROTECT if they're already taking supplements that seem less effective than before. Others prefer addressing multiple pathways together for synergistic benefits.

What most people find: Starting somewhere, even imperfectly, teaches you what your body responds to. The first positive change usually happens within the first two weeks. That initial improvement often clarifies what to adjust next.

The research provides the map. Your experience becomes the compass.

Common Questions.

Can't I just take NMN?

You can, but you're leaving 75% of the benefits on the table. It's like having a sports car but only using first gear.

How long until I feel results?

Most people notice energy improvements in 3-7 days. Deeper benefits (recovery, cognitive, metabolic) typically emerge by week 3-4.

Is this safe long-term?

Every ingredient has extensive safety data in human and animal models. Our dosing strategies reflect the standards set by researchers for safe use.

This sounds too good to be true

It would be if we were claiming one pill fixes everything. We're not. This is about systematically addressing multiple failure points in a well-studied biological system. The research is published in Science, Nature, Cell, established scientific journals, not wellness blogs.

Why doesn't my doctor know about this?

Medical education focuses on disease treatment, not optimization. NAD⁺ biology has exploded in the last decade. Most physicians trained before this research emerged, and even if it was covered, most doctors aren’t focused on longevity as a subspecialty. Additionally, you can't patent NAD⁺ or its precursors since they’re natural molecules and are made inside the body, so there's limited pharmaceutical interest in education for funding reasons.

Does this just make expensive urine?

Valid concern. Raw NAD⁺ precursors without supporting pathways can have poor utilization. That's exactly why the four-pathway approach exists: to ensure what you take gets used, not excreted. The PROTECT pathway specifically addresses this by reducing wasteful consumption.

What about side effects?

At physiological doses, side effects are minimal. Some people experience initial sleep changes (as circadian rhythms adjust), or digestive changes (as the microbiome adapts). These typically resolve within days. Start low, increase gradually. Always check for ingredient interactions if you're on prescriptions or are under the care of a physician.

What about side effects?

At physiological doses, side effects are minimal. Some people experience initial sleep changes (as circadian rhythms adjust), or digestive changes (as the microbiome adapts). These typically resolve within days. Start low, increase gradually. Always check for ingredient interactions if you're on prescriptions or are under the care of a physician.

Who Benefits Most from NAD⁺ Restoration?

While everyone over 30 has declining NAD⁺, certain people see more dramatic improvements:

  • High Performers: Entrepreneurs, athletes, parents juggling careers and kids: people who need sustained energy see immediate benefits from optimized NAD⁺ levels.
  • The Metabolically Challenged: If you have insulin resistance, metabolic issues, or stubborn weight, NAD⁺ restoration improves how cells handle glucose and burn fat.
  • Poor Sleepers: Those who wake exhausted despite adequate sleep often have impaired cellular regeneration. NAD⁺ restoration can improve sleep quality at the cellular level.
  • Chronic Stress Cases: Stress depletes NAD⁺ faster.³⁴ If you're in a demanding phase of life, you're burning through NAD⁺ at an accelerated rate.
  • Anyone Over 45: This is when NAD⁺ decline accelerates. The difference between supplementing and not becomes increasingly apparent with each passing year.
  • The Biohacker Curious: If you're already optimizing diet, exercise, and sleep, NAD⁺ is the next logical frontier: it amplifies everything else you're doing.
Bryan Nettles, CEO

The Choice Is Yours.

Every day you wait, NAD⁺ levels drop a little more. CD38 increases. Mitochondria get less efficient. The gap between how you feel and how you could feel widens.

Or you can take control. Use all four pathways. Restore your NAD⁺ systematically, scientifically.

  • Still skeptical? Start with just the morning BOOST protocol for 30 days. If you don't feel the difference, we'll refund every penny. That's how confident we are in the science.
  • Have questions? Our longevity specialists are here to help. Chat with us below or email support@renuebyscience.com

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