If you’re over 40 and using CollagenX 40up protein powder, chances are you started for one reason:
to stay strong, lean, and capable in a body that doesn’t respond to training the way it used to.

That frustration has a name — anabolic resistance — and 40up was built specifically to overcome it.

But science has a way of revealing unexpected wins. And recent research is now showing that the same amino acids helping your muscles respond again may also be doing something quietly powerful in the background: protecting your liver and supporting metabolic health.

This is one of those rare moments where the science genuinely delivers good news.

Why Building Muscle After 40 Feels Different

As we age, our muscles become less sensitive to protein. You can eat plenty of it, train consistently, and still fail to trigger the muscle-building response you once took for granted.

Researchers call this anabolic resistance. What they’ve learned is that older muscle needs a clearer, stronger signal — and that signal comes primarily from leucine.

Leucine acts like a molecular switch. When it reaches a certain threshold, it activates the mTOR pathway and tells muscle tissue, “It’s time to build and repair.” Below that threshold, the signal is weak. Above it, the response improves dramatically.

This is why 40up delivers a full 3 grams of leucine per serve — the amount repeatedly shown to overcome anabolic resistance in people over 40.

But leucine is only part of the story.

The Glycine Connection No One Was Talking About

For years, glycine was viewed as a “simple” amino acid — helpful for connective tissue, sleep, and recovery, but rarely centre stage.

That changed with a major study published in Science Translational Medicine, where researchers looked at glycine’s role in non-alcoholic fatty liver disease (NAFLD) and its more severe form, NASH.

Unlike many experimental studies that use unrealistically high doses, this research focused on human-equivalent oral dosing, making the findings far more relevant to real life.

What they discovered was striking.

Low glycine availability wasn’t just associated with fatty liver — it appeared to be part of the problem.

When glycine was added back in:

• Liver fat accumulation dropped
• Inflammation decreased
• Glucose and lipid metabolism improved
• Weight gain from high-fat diets was reduced

And crucially, the researchers were able to define clear therapeutic doses for humans.

The Exact Doses That Made the Difference

Using established mouse-to-human conversion models, the study identified:

• A minimum effective dose of about 27 mg of glycine per kg of body weight per day
• Optimal effects at around 40 mg/kg per day

For most adults over 40, that equates to roughly 2–4 grams of glycine daily.

Now here’s where this becomes directly relevant to 40up users.

Each serve of 40up provides approximately 4.5 grams of glycine — placing it squarely within the optimal therapeutic range identified in the study, even for larger individuals.

This isn’t incidental. It means that one serve of 40up delivers glycine at a level shown to influence liver fat metabolism, inflammation, and metabolic health.

Why Glycine and Leucine Work Better Together

The study didn’t stop at glycine alone.

In a search for more potent metabolic effects, researchers tested a glycine–glycine–leucine tripeptide (known as DT-109). This combination outperformed glycine on its own in improving fatty liver disease, inflammation, and obesity-related outcomes.

The reason comes down to biology.

Leucine improves metabolic signaling and nutrient sensing. Glycine supports mitochondrial function, reduces oxidative stress, and dampens inflammatory pathways. Together, they improve how the body handles both energy and protein — particularly under the metabolic stress that often accompanies aging.

This combination has been studied extensively by researchers associated with Michigan Medicine, who noted that glycine-based interventions may offer real promise in a field where no approved pharmaceutical treatments for NAFLD currently exist.

What Makes 40up Different for People Over 40

This is where the formulation of 40up quietly stands apart.

In a single serve, you’re getting:

• 3 grams of leucine — enough to clearly signal muscle protein synthesis despite anabolic resistance
• 4.5 grams of glycine — meeting or exceeding the doses shown to improve liver fat metabolism in the study

That means your daily protein routine isn’t just aimed at muscle. It’s influencing systems that control inflammation, glucose handling, and fat storage — especially in the liver.

And importantly, glycine has an exceptional safety record. Human studies have used doses many times higher than those in 40up without adverse effects, making these intakes both effective and conservative.

Why This Matters More After 40

Fatty liver disease is now one of the most common chronic conditions in adults over 40 — often developing silently, without symptoms or obvious warning signs.

At the same time:

• Muscle mass declines
• Insulin sensitivity worsens
• Fat gain becomes easier
• Recovery slows

The emerging science suggests that addressing amino acid needs — particularly glycine and leucine together — may help counter multiple aspects of this age-related decline at once.

That’s not hype. It’s a rare example of nutritional overlap where one strategy supports multiple systems.

The Bigger Picture

The most encouraging part of this research isn’t just the data — it’s what it means in real life.

If you’re using 40up consistently, training sensibly, and prioritising protein, you’re not just fighting muscle loss. You may also be supporting your liver, calming inflammation, and improving metabolic resilience in ways science is only now fully appreciating.

That’s the kind of good news worth sharing.