Researchers Believe Declining NAD Levels May Be the Central Cause of Nearly Every Aging Complaint After 40
Thu. March 12th, 2026 | 6:00 am EST
This health writer breaks down what longevity researchers say may be the most overlooked discovery in aging science.
By Sarah Mitchell
Health & Wellness Correspondent
If you've been following the latest aging trends you've probably heard of NAD+.
Scientists have been studying it quietly for years.
And what they found finally explains something millions of people over 40 experience.
Weight creeping up no matter how clean you eat.
Energy disappearing by early afternoon no matter how much you sleep.
Joints instantly aching when you wake up.
Losing your drive and your mood changing every second.
Wrinkles and sagging appearing on your face.
Your hair getting thinner.
Most people go through these changes one by one and blame anything:
Diet. Stress. Age. Hormones. Genetics.
You go see a doctor but your bloodwork comes out "normal".
So you go back home with no real explanation and no real solution.
And they found all these problems have one common cause...
What scientists found at the cellular level
Every cell in your body runs on energy.
Not the kind of energy you feel after coffee.
Real cellular energy produced deep inside your mitochondria.
This process depends entirely on NAD+.
It's not a vitamin and it's not a hormone.
It sits at the centre of every energy, repair and regulation system in our bodies.
It powers proteins that control your metabolism and fat burning.
Fuels enzymes that repair your DNA and keep your cells clean.
Tells your body when to rest, recover and rebuild.
Keeps inflammation away from your joints, skin and everywhere else in your body.
And stabilizes your hormones.
Without enough NAD+ your body can't function properly.
After turning 40, NAD+ levels drops by 50%.
By mid-50s most people only have a fraction left of what their body had at 30.
This one deficiency's the reason behind these changes people think is just "getting older".
What Happens Deep Inside Your Cells When NAD+ Drops
Your cells don't all fail at once.
Over time they become less and less efficient depending on each system.
For metabolism, NAD+ powers a protein called SIRT1 which regulates fat burning.
So when NAD+ levels drop your body stops burning fat and starts storing it. (especially around your belly)
For your energy system NAD+ is the molecule that carries ATP throughout your entire body.
ATP is our body's energy currency.
So low NAD+ levels causes low ATP production which makes you always feel drained.
For joints, NAD+ fuels repair proteins stopping inflammation and rebuilding tissue after wear.
In terms of hormones, NAD+ plays a direct role in how your cells respond to hormonal signals.
When NAD+ levels decline those signals weaken.
Which is why you feel off even if your bloodwork comes in "normal".
Lastly for your skin and hair.
Skin relies on cells that produce collagen and elastin to maintain its structure.
And hair follicles have the same fate.
Both need NAD+ to power the energy allowing them to keep building and repairing.
All different problems.
The same root cause.
Why does this happen?
First, cells accumulate daily damage from stress, toxins and normal wear and tear.
To repair those damages your body sends enzymes which consume NAD+.
Second, an enzyme called CD38 becomes more active with age.
Its job is to break down NAD+.
And older tissue can contain 2-3x more of it than younger tissue.
Third, your body becomes less and less efficient at making and recycling NAD+.
This system slows down and starts producing less NAD+ while using more of it.
Together, these processes slowly drain your NAD+ reserves year after year.
By the time you notice any effects the damage has already been building up...
What scientists discovered: the NAD+ messenger
Our bodies don't produce NAD+.
They build it using a natural compound called NMN.
Or Nicotinamide mononucleotide.
NMN exists naturally in the body and can be found in trace amounts in certain foods.
It enters your cells to then transform into NAD+.
So why not just take NAD+ directly?
Researchers tried that.
The problem is NAD+ molecules are too big to pass through cell membranes on their own.
Most of it would just get broken down by digestion before it even reaches your cells.
NMN is way smaller and actually gets through cell membranes.
In clinical trials, researchers gave NMN to aging subjects.
They're NAD+ levels increased by up to 38%.
NMN doesn't spike and crash your energy like caffeine.
It doesn't suppress appetite.
And it doesn't block or force anything.
It simply gives your cells what they need to produce more NAD+.
For most people this can change everything.
Benefits of High NAD+ Levels
When NAD+ levels rise, researchers noticed it wasn't one benefit, it was multiple.
Energy stabilizes. No more crashing in the afternoon.
Metabolism starts working again. Cravings and stubborn belly fat start going away.
Joints stop hurting. Morning stiffness goes away in minutes instead of hours.
Drive and vitality return.
Skin health improves. Softer skin and fine lines start fading away.
Hair health improves. Hair starts growing and gets thicker.
Even grey hair slowing down and dark pigment returning at the roots.
Better sleep. Boosting NAD+ levels supports your circadian rhythm which affects sleep quality.
You'll notice a boost in energy within the first week.
And within 2-4 weeks you'll start seeing more of these benefits appear.
But the real magic begins after the three-month mark.
The key is to stay consistent.
What To Know Before Buying NMN
Not all NMN is what it claims to be.
An independent study tested 22 top-selling NMN supplements.
They found out 64% of them contained less than 1% of the NMN stated on the label.
Meaning the majority of people who tried NMN and felt nothing weren't actually taking NMN.
That's why people say NMN "doesn't work".
The product failed them, not NMN.
But purity is only part of the problem.
Even high-quality NMN on its own may not be enough.
Researchers studying NMN found it works best with the right supporting ingredients.
These ingredients help protect NAD+ from being broken down too quickly.
But they also help get better and faster results.
The best formulas are built to efficiently raise NAD+ and make sure your cells can actually use it.
Introducing CLERO's 10-in-1 NMN
CLERO solves both of those issues.
Every batch uses independently tested, verified high-purity NMN.
No misleading labels and no hiding what's actually inside.
CLERO doesn't stop there.
Alongside NMN CLERO includes 9 other carefully chosen ingredients.
Each one addresses a specific part of what happens when your body ages at the cellular level.
And all it takes is one capsules a day.
CLERO's Once In A Lifetime Offer
CLERO's NMN supplement is now available for $0.83 a day.
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That's $49.99 for one 2-months supply bottle.
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So you can try 3 bottles of CLERO's NMN risk-free.
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