Yes, you absolutely can!

Unlike regular white fat, which stores excess calories, brown fat acts like a cellular furnace. One of its main functions is to generate heat to keep us warm. It does this by burning through stored fat and sugars using a specialized protein called UCP-1 (Uncoupling Protein-1), which effectively short-circuits our cellular energy production to release the energy in fat and sugar as pure heat.

Here is how our bodies manage this tissue, and how science is trying to help us grow more of it.

 

Use It or Lose It: The "Plasticity" of Brown Fat

Our bodies are highly efficient. Maintaining active tissue takes energy, so the body operates on a strict budget. Just as muscles shrink (atrophy) when you stop lifting weights, brown fat volume decreases when it isn’t needed.

Thankfully, the reverse is also true. Brown fat is highly plastic, meaning it can expand or shrink based on demand. When your body realizes it needs more heat, it calls upon progenitor cells (adult stem cells) to recruit and build brand-new, fully functional brown fat cells.

 

Method 1: Turn Down the Thermostat (The Natural Method)

The most natural way to build brown fat is through cold exposure. As seasons change and autumn turns to winter, our brown fat reserves naturally build up to help us cope with the cold. [1]

We can also trigger this in a lab:

The Study: In a well-known clinical study, participants slept in a cool room (19°C / 66°F) for just one month. [2]

The Result: They experienced a nearly 40% increase in brown fat volume and a doubling of its metabolic activity.

The Catch: This change is entirely reversible. When the same participants spent the following month sleeping in a warm room (27°C / 81°F), their brown fat shrank back down to below their starting levels.
 

Method 2: The Pharmaceutical Route (And Why It’s Tricky)

Scientists have also successfully increased brown fat using medication. One prime example is mirabegron, an FDA-approved drug typically used to treat overactive bladder.

Mirabegron works by stimulating beta-3 adrenergic receptors, which happen to be the same chemical "on-switches" that tell brown fat to activate and grow. In an NIH-led clinical trial [3], healthy women who took mirabegron daily for 10 weeks saw:

   - A significant increase in brown fat volume and metabolic activity

   - Improved insulin sensitivity

   - Higher levels of HDL ("good") cholesterol
 

The Problem: Stimulating beta receptors with mirabegron also raises heart rate and blood pressure. Those cardiovascular effects are a meaningful limitation for long-term use, and mirabegron is not approved for obesity or other metabolic conditions.

 

The Future: Waking Up Our "Sleeping" Stem Cells

The ultimate goal for researchers is to find a way to grow new brown fat without stressing the heart.

This is where stem cell research comes in. Scientists at Energesis identified and characterized human brown fat progenitor cells, the stem-like cells involved in making new brown fat. By screening thousands of compounds, including existing approved medications and novel molecules, our researchers have identified candidates that, in laboratory studies, prompt these cells to mature into brown fat cells without acting through the beta-3 pathway associated with mirabegron’s cardiovascular effects. Our goal is to continue to test the best of these candidates that increase brown fat without relying on beta-3 stimulation.

 

An important caveat: These are preclinical results. Our investigational candidates have not been tested in humans, are not approved by any regulatory authority, and there is no assurance they will prove safe or effective. Preclinical findings may not translate to humans.

 

The Best News? Most of Us Appear to Have Them.

By analyzing tissue samples from dozens of individuals, researchers at Energesis found that these brown fat progenitor cells were present in all of the individuals studied. While not a guarantee that every individual has these cells, across the age range studied, including adults up to 80 years old, and across biological sex and body mass index (BMI), the cellular machinery to build new brown fat appears to remain intact.

In large part, we appear to keep the biological blueprint to regenerate our internal furnaces. Finding the right key to turn them back on is the focus of our ongoing research.

 

Sources

 

1. Brown Adipose Tissue and Seasonal Variation in Humans

Au-Yong, I. T., Shen, J., Lim, M. J., ... & Symonds, M. E.

Diabetes, November 2009 (Vol. 58, No. 11). doi.org/10.2337/db09-0833

2. Acclimation to Cold Rebuilds Brown Fat and Increases Insulin Sensitivity in Humans 

Lee, P., Smith, S., Linderman, J., ... & Celi, F. S.

Diabetes, 2014 (Vol. 63, No. 11). doi.org/10.2337/db14-0513

3. Activation of human brown adipose tissue by a β3-adrenergic receptor agonist

Aaron M Cypess 1, Lauren S Weiner 2, Carla Roberts-Toler 2, Elisa Franquet Elía 3, Skyler H Kessler 2, Peter A Kahn 4, Jeffrey English 3, Kelly Chatman 5, Sunia A Trauger 5, Alessandro Doria 6, Gerald M Kolodny 3

Cell Metab. 2015 Jan 6;21(1):33-8. doi: 10.1016/j.cmet.2014.12.009.

4. A reservoir of brown adipocyte progenitors in human skeletal muscle

Crisan M, Casteilla L, Lehr L, Carmona M, Paoloni-Giacobino A, Yap S, Sun B, Léger B, Logar A, Pénicaud L, Schrauwen P, Cameron-Smith D, Russell AP, Péault B, Giacobino JP.

Stem Cells. 2008 Sep;26(9):2425-33. doi: 10.1634/stemcells.