Researchers Identify Two Distinct Chemical Mechanisms Behind the Overthinking Brain and the Adaptogen Stack That Addresses Both 

There is a particular kind of exhaustion that comes with an overthinking brain. Not the pleasant tiredness of having thought deeply about something — but the grinding fatigue of a brain that cannot stop monitoring itself. Mid-conversation, you are not fully listening. You are watching. Tracking your own tone. Replaying what you just said. Calculating how your expression must look to the other person right now. And by the time the conversation ends, you have barely been present for a moment of it. Most people who experience this are told it is a psychological problem — a habit to rewire, a mindset to change. The science tells a different story. There are two specific chemical imbalances in the brain that drive the overthinking, self-monitoring state. And a targeted combination of plant-based compounds now has real human clinical data for addressing both of them.

Your brain runs on a system of chemical signals that either speed it up or slow it down.

The main "speed up" chemical is called glutamate. It drives neuronal activity — keeps the brain firing, alert, and engaged. The main "slow down" chemical is called GABA. Its job is to quiet that neural activity and help the brain return to a resting state when nothing important is actually happening.

In a healthy brain, these two chemicals stay balanced. When something genuinely demands your attention, glutamate spikes. When it passes, GABA brings things back down. The brain engages, then disengages.

In people with chronic anxiety and overthinking, this balance tips toward glutamate — and stays there. The brain keeps firing at elevated levels even when nothing in the environment warrants it. Researchers call this glutamate dominance, and they have measured it directly using brain imaging. A review of 26 clinical brain imaging studies found elevated glutamate levels specifically in the regions of the brain responsible for self-monitoring — the parts that generate the experience of watching yourself from the outside during a conversation.

When those regions are running hot with excess glutamate, the self-monitoring loop stays switched on. Not because there is a real threat. Because the chemistry that would normally quiet it back down is not strong enough to do so. This is also why thinking your way out of overthinking rarely works. Knowing you are overthinking does not change the chemistry driving it.

The second mechanism runs through your body's stress hormone system — and it makes the first problem worse.

Cortisol is the hormone your body releases when it senses a threat. Under normal conditions, your body produces cortisol, deals with the stressor, and then resets back to a calm baseline. There is a built-in feedback loop — think of it as a cortisol thermostat — that pulls levels back down once the threat has passed.

In people with chronic anxiety, this thermostat breaks. Cortisol stays elevated long after any actual threat has passed. The system keeps pumping out the "emergency" signal even when there is no emergency in sight.

This creates two specific problems in the brain. First, high cortisol steadily reduces function in the prefrontal cortex — the part of your brain responsible for rational thinking, context, and keeping emotional reactions in proportion. Second, it amplifies the amygdala, which is your brain's threat-detection centre, making it more reactive and hair-trigger sensitive to everything around you.

The result is a brain that is simultaneously less rational and more threat-sensitive. That is the chemistry behind walking into a room and immediately scanning for every possible way things could go wrong.

And here is where the two mechanisms combine. High cortisol directly suppresses GABA — the calming chemical from the first mechanism. So elevated cortisol means less GABA. Less GABA means more glutamate dominance. More glutamate means more self-monitoring and hypervigilance. Which creates more perceived threat. Which creates more cortisol. The loop feeds itself, with no natural off switch.

Here is where the research gets interesting.

There is a category of plant compounds called adaptogens. Unlike pharmaceutical anxiety medications, which essentially flood the brain with artificial calming signals and carry real dependency risks, adaptogens work with your brain's own chemistry. They help restore what the chemistry is supposed to do on its own.

Three of them in particular have human clinical evidence for addressing both mechanisms described above: Ashwagandha, Shilajit, and Tongkat Ali.

On the glutamate-GABA problem, Ashwagandha and Shilajit both exhibit what researchers call GABA-mimetic activity. That means they bind to your GABA receptors and activate them — essentially doing the job that GABA is supposed to do, but is not doing strongly enough. Worth noting: when people try to take GABA as a supplement directly, it barely crosses into the brain. But the active compounds in Ashwagandha and Shilajit do. A randomized controlled trial in 60 adults showed that KSM-66 Ashwagandha (the standardized extract) produced significant anxiety improvements over eight weeks, with researchers pointing to enhanced inhibitory signaling as the mechanism — not sedation.

This distinction matters. The goal is not to blunt your brain. The goal is to give your brain's own calming system enough traction to actually work.

Ashwagandha has more peer-reviewed human studies on cortisol reduction than any other plant-based compound in this category.

The most cited is a double-blind, placebo-controlled trial published in the Indian Journal of Psychological Medicine (2012). Adults with chronic stress took KSM-66 Ashwagandha at 300mg twice daily for 60 days. The result: a 27.9% reduction in serum cortisol compared to their own starting levels. The placebo group showed no meaningful change. The statistical confidence level on that result was p < 0.001 — among the strongest you can get in this kind of research.

In the same study, the Ashwagandha group also showed a 44% drop in Perceived Stress Scale scores. The researchers concluded the anxiety improvements were driven by the cortisol normalization — not by any sedative effect on the brain.

Tongkat Ali adds a second layer of cortisol modulation — hitting a different point in the stress hormone chain than Ashwagandha does.

In a separate placebo-controlled trial published in the Journal of the International Society of Sports Nutrition (2013), moderately stressed adults taking standardized Tongkat Ali extract showed a 16% reduction in salivary cortisol compared to the placebo group. They also reported significant improvements in tension, anger, and general mood.

Think of it this way: Ashwagandha acts on the brain signal that starts the cortisol cascade. Tongkat Ali acts on the adrenal response at the other end of that chain. Together, they reduce cortisol output at two separate points — which means the combined effect on cortisol is greater than either compound alone.

Most supplements in this space target one thing. Either they try to increase GABA, or they try to lower cortisol. Rarely both — and rarely with solid human clinical evidence behind the mechanism they are claiming.

The glutamate-GABA problem and the cortisol problem are two separate issues that produce the same experience: a brain stuck in overdrive, unable to stop watching itself.

If you address only one while the other keeps running, the chemistry of the overthinking state is only half-corrected. This is likely why many people find individual supplements give partial relief at best. The root cause is not being fully addressed.

For anyone who has spent years in their own head — replaying conversations, monitoring every word mid-sentence, unable to just be present — the research here offers something more useful than a mindset tip. The overthinking brain is not a personality flaw or a bad habit. It is a brain operating under two specific, measurable chemical conditions. Both of which can be addressed.

Adaptogens like those in COMPOSURE+ do not manufacture calm by overriding the brain. They restore the chemical conditions your brain needs to calm itself down on its own — so that presence becomes your default instead of performance, and stillness replaces surveillance.