Landmark New Retatrutide Study

Happy Tuesday!

Today, I’m bringing you a bombshell new clinical trial, published in June 2025, that gives us hard data on how the most exciting peptide in the world (retatrutide) actually changes your body composition.

But as always, I’m not here to hype up pharma for pharma’s sake.

I want you to win, and that means taking your peptide stack to the next level.

So we’ll break down what this 2025 Lancet D&E study actually found, how it compares to the other “big name” weight loss drugs, and how you can stack retatrutide with mitochondrial uncouplers (BAM15) and metabolic activators (SLU-PP-332) to defend every last ounce of lean muscle, not just lose weight.

Here’s a link to the study:

The Study

First, let’s get into the design.

The research team ran a gold-standard, double-blind, randomized controlled trial, including a DEXA substudy piggybacking off the major retatrutide phase 2 trial for type 2 diabetes.

• Participants: Adults with type 2 diabetes and overweight or obesity.

• Intervention: They received weekly injections of retatrutide (at various doses, with 8 mg being the key “sweet spot”) and were tracked for 36 weeks.

What makes this study so critical is that they used DEXA scans to measure exactly how much of the weight lost was fat, and how much was muscle.

If you’ve ever dieted hard and watched your muscles deflate, you know this is the million-dollar question in the world of weight loss.

The control group included people on dulaglutide (a GLP-1–only drug) and a placebo, so we could see how retatrutide really stacks up.

The Results

So, what did they find?

At 36 weeks, participants taking 8 mg of retatrutide lost, on average, a staggering 26.1% of their total fat mass (via DEXA).

This was pure fat.

And remember, these people are changing NOTHING about their daily lives (other than just eating less because of the effects of the drug).

The lean mass (“muscle”) loss was approximately 20–40% of the total weight lost, meaning that a solid 60–80% of the weight loss was actual fat, not lean tissue.

For comparison, the control group (on dulaglutide or placebo) lost just a fraction of that.

Placebo lost approximately –4.5% of their fat mass, while dulaglutide lost about –2.6%.

Retatrutide produced the largest absolute fat loss ever recorded in an obesity/diabetes drug trial.

And it did so with about the same lean mass preservation as the “best” current drugs.

Fat vs Muscle

Every time you lose weight, even with the “miracle” GLP-1 drugs, some of it is going to be muscle, not just fat.

The proportion matters.

Losing too much muscle can tank your metabolism, weaken your strength, and set you up for a rebound.

Lose mostly fat, and you preserve your engine for the long run.

This 2025 DEXA study shows that the ratio of fat-to-muscle loss is basically the same as you’d get with tirzepatide or semaglutide, but you get way more total fat loss.

In other words, retatrutide supercharges the process without making the muscle loss any worse.

This is a game-changer, especially for anyone who wants to look, feel, and perform at their best.

Why I Recommend Stacking BAM15 and SLU-PP-332 With Retatrutide

If you’re part of my crew, you want to do better than everyone else, and the right stack can help you do just that.

Enter BAM15 and SLU-PP-332.

• BAM15 is a next-gen mitochondrial uncoupler. It increases your body’s energy expenditure without ramping up your heart rate, helping you burn more fat for the same amount of calories. Studies have shown that BAM15 not only enhances fat loss, but may also help preserve lean mass by shifting the body’s substrate utilization (Study here).

• SLU-PP-332 is a small-molecule metabolic activator shown in recent preclinical studies to increase mitochondrial biogenesis, promote fat oxidation, and blunt muscle wasting under caloric restriction or pharmacologic fat loss (Study here).

When you combine these with retatrutide, you create a three-pronged approach:

1. Maximal fat loss (retatrutide)

2. Extra calorie burn without muscle loss (BAM15)

3. Protection of lean mass and enhanced energy output (SLU-PP-332)

Why This Matters for You (and Where to Get the Stack)

So what does this all mean for you?

If you want to go beyond the basic weight loss everyone else is getting, the combination of retatrutide, BAM15, and SLU-PP-332 is one of the closest things to a physique “reset button” we have right now.

Don’t fall for the trap of “weight loss at all costs.”

Your metabolism, strength, and long-term success depend on preserving as much muscle as possible while dropping the fat.

For a limited time, you can get 20% off both of these products, plus an additional 15% off when you use code HUNTERW at checkout.

Wrapping Up

The 2025 retatrutide DEXA study proved that you can lose more fat than ever before, without losing more muscle than you’d expect from any other “miracle” peptide.

But if you want the best body comp, the best energy, and the best shot at keeping the fat off for good, you owe it to yourself to stack smart, stack early, and stack with intention.

Best,

Hunter Williams