What Tirzepatide Does To Brown Fat

Firstly, for any unfamiliar with tirzepatide, it’s a GLP-1 drug, but as well as boosting the action of GLP-1 (glucagon-like peptide 1) receptors, it also acts simultaneously on GIP (glucose-dependent insulinotropic peptide) receptors, thus adding a second mechanism of action.

For this reason, it is more effective than its predecessors, including Ozempic:

❝The first GLP-1 mimicking drug was exenatide (Bayetta). It’s still available for treating type 2 diabetes, but there are currently no generics. Exenatide does provide some weight loss, but this is quite modest, typically around 3-5% of body weight.

For liraglutide, those using the drug to treat obesity will use the stronger one (Saxenda), which typically gives about 10% weight loss.

The newest GLP-1 mimicking drug on the market, tirzepatide (Mounjaro for type 2 diabetes and Zepbound for weight loss), results in weight loss of around 25% of body weight.❞

Read in full: Ozempic’s cousin drug liraglutide is about to get cheaper. But how does it stack up?

You can also read more about tirzepatide in our main feature about it, here: Mounjaro/Zepbound’s Stable Weight Loss Curve

But now, there’s newer news, and today we’re going to talk about…

Burning the BAT

…which may sound like the name of a Meat Loaf album or something, but no, it’s about brown adipose tissue (BAT), which we wrote about here, in the context of when the body slows down / stop producing this particular kind of fatty tissue: The BAT-pause!

You may be wondering: if it’s so good, to the point that you wrote an article about the methods and merits of converting white adipose tissue to brown, why do we want tirzepatide to affect the brown?

And the answer lies in the thermogenesis prompted by BAT activation.

Researchers (Dr. Marion Peyrou et al.) found that tirzepatide directly activates brown adipose tissue, increasing thermogenic activity and upregulating genes linked to thermogenesis and substrate oxidation independent of calorie reduction.

Translating that from sciencese: it made the fat work better for energy metabolism

So, what of white adipose tissue in all of this? In the study, white adipose tissue showed distinct changes mainly in lipid metabolism, with a trend toward greater visceral and subcutaneous fat reduction in the tirzepatide group.

In other words, a healthy reduction of fat in the places people are usually trying to lose it from, in large part as a knock-on effect of the BAT-activation, and (importantly!) independent of reduction in food intake (so, not dependent on the main mechanism of action of GLP-1 drugs).

As a special bonus, unlike previous attempts to pharmacologically activate brown fat, which often caused cardiac side effects, tirzepatide appears to activate brown adipose tissue while showing cardiovascular benefits.

You can read the paper in full, here: Differential effects of the anti-obesity drug tirzepatide on adipose tissues: Brown fat as a key target

Want to learn more?

You might like this book that we reviewed a little while back:

Magic Pill: The Extraordinary Benefits and Disturbing Risks of the New Weight-Loss Drugs – by Johann Hari

Enjoy!