You work out. You eat reasonably well. You get enough sleep — most nights. But somewhere in your 40s or 50s, something shifts. Recovery takes longer. Energy isn't what it was. You feel like you're doing everything right and still falling behind.

The answer isn't always in your gym program or your diet. Sometimes it's happening at a level you can't see: inside your cells.

Two molecules — NAD+ and glutathione — sit at the center of how your cells produce energy, repair damage, and defend themselves against aging. And both decline significantly as you get older. Understanding what they do, why they drop, and how to restore them is one of the most important things you can do for your long-term health.

What Is NAD+ and Why Does It Matter?

NAD+ (nicotinamide adenine dinucleotide) is a coenzyme found in every cell in your body. It plays a central role in two of the most critical cellular processes you have:

Energy production. NAD+ is essential for your mitochondria — the power plants of your cells — to convert food into ATP, the fuel your body actually runs on. Without adequate NAD+, your cells can't produce energy efficiently. You feel it as fatigue, brain fog, and sluggish recovery.

DNA repair and longevity signaling. NAD+ activates a class of proteins called sirtuins, which regulate DNA repair, inflammation, and cellular aging. It also fuels PARP enzymes, which patch damaged DNA strands before they accumulate into dysfunction. Think of NAD+ as both the fuel and the maintenance crew for your cellular machinery.

Here's the problem: NAD+ levels drop by roughly 50% between your 20s and your 50s. By the time most men start noticing the signs of aging — slower metabolism, reduced muscle recovery, declining cognitive sharpness — their NAD+ levels have already been falling for years.

What Is Glutathione and Why Does It Decline?

Glutathione is your body's master antioxidant. It's produced inside your cells (primarily in the liver) and serves as the frontline defense against oxidative stress — the cellular damage caused by free radicals that accumulates with age, illness, and chronic inflammation.

Beyond antioxidant protection, glutathione plays a critical role in:

• Detoxification — binding to toxins, heavy metals, and metabolic waste products so they can be safely eliminated
• Immune function — supporting the activity of white blood cells and regulating inflammatory responses
• Mitochondrial protection — shielding the very organelles that produce your energy from oxidative damage
• Protein synthesis and repair — maintaining the structural integrity of cells and tissues

Like NAD+, glutathione levels decline with age — and the decline accelerates under stress, poor sleep, alcohol consumption, and chronic inflammation. By your 40s and 50s, most men are running on a significantly depleted antioxidant reserve. The result is faster cellular aging, slower recovery, and a body that's less equipped to handle the demands you put on it.

What Happens When Both Decline Together

NAD+ and glutathione work in concert. NAD+ powers the energy systems that keep cells functioning; glutathione protects those same cells from the oxidative byproducts of that energy production. When both are low simultaneously — which is the norm in aging men — the effects compound.

You get mitochondria that are both underpowered and unprotected. Cells that can't repair DNA efficiently and can't neutralize the damage accumulating from that failure. An immune system that's reactive rather than resilient. A metabolism that's slower, a recovery window that's longer, and a body that feels older than it should.

This is the biological reality behind what most men chalk up to "just getting older."

Where Sermorelin Fits In

Sermorelin is a growth hormone-releasing peptide — a synthetic version of the natural signal your hypothalamus sends to your pituitary gland to produce growth hormone (GH). Unlike synthetic HGH, sermorelin works with your body's own regulatory systems, stimulating a natural, pulsatile release of GH rather than flooding your system with exogenous hormone.

Growth hormone plays a direct role in the same systems that NAD+ and glutathione support:

• Cellular repair and regeneration — GH stimulates IGF-1, which drives tissue repair, muscle protein synthesis, and recovery
• Metabolic function — GH supports fat metabolism and lean muscle preservation, both of which decline with age
• Sleep quality — the majority of GH is released during deep sleep; sermorelin can improve sleep architecture, which in turn supports both NAD+ recycling and glutathione synthesis
• Mitochondrial health — GH signaling supports mitochondrial biogenesis, the process of building new, healthy mitochondria

When you combine sermorelin with NAD+ and glutathione support, you're addressing the problem from multiple angles at once. Sermorelin restores the hormonal signal that drives cellular repair. NAD+ provides the fuel for that repair to actually happen. Glutathione protects the cells doing the work from oxidative damage in the process.

The synergy is real. Men who add sermorelin to a protocol that already includes NAD+ and glutathione often report faster recovery, better sleep, improved body composition, and a more sustained energy level throughout the day — not the artificial spike of stimulants, but a deeper, more durable vitality.

The Weight Loss Connection

One of the most frustrating aspects of aging for men is the shift in body composition — fat accumulates around the midsection while muscle becomes harder to build and easier to lose. This isn't a willpower problem. It's a hormonal and metabolic one.

Declining testosterone, growth hormone, and insulin sensitivity all contribute to this shift. So does the mitochondrial dysfunction that comes with low NAD+. When your cells can't produce energy efficiently, your body becomes more likely to store fat and less able to burn it.

Restoring NAD+ improves mitochondrial function and insulin sensitivity, making your metabolism more responsive. Glutathione reduces the chronic inflammation that drives insulin resistance and fat storage. Sermorelin supports GH-driven fat metabolism and lean muscle preservation.

Combined with testosterone optimization — the foundation of most protocols at Gables — these therapies create the metabolic environment your body needs to actually respond to your efforts in the gym and at the table.

How We Approach This at Gables Men's Health

At Gables, we don't believe in one-size-fits-all protocols. Every man who walks through our door gets a comprehensive lab panel and a physician consultation before anything is prescribed. We look at your testosterone, estradiol, IGF-1, metabolic markers, inflammatory markers, and more — because the goal isn't to treat a number. It's to understand what's driving your symptoms and build a protocol that addresses the root cause.

For many of our patients, NAD+ and glutathione aren't add-ons. They're foundational. They're the cellular infrastructure that makes everything else — TRT, sermorelin, peptide therapy — work better and last longer.

We also understand that results take time and that the goal isn't a quick fix. It's building a version of yourself that performs at a high level for decades, not just months. That means optimizing your hormones, restoring your cellular health, and giving your body the tools it needs to repair, recover, and thrive.

If you're ready to stop guessing and start understanding what's actually happening in your body, we're here to help you figure it out.