The Science of Stress and Burnout
A Guide to Adaptogens and When to Use Them
For a long time, stress was treated like a purely emotional experience. Something you could solve with a vacation, a yoga class, or a night out with your friends. But the reality is that stress is also deeply biological. It shapes hormones, metabolism, immune activity, and even how the brain communicates with the rest of the body.
At the center of this process is the HPA axis, which stands for the hypothalamic–pituitary–adrenal axis. This system is essentially the body’s stress command center. The hypothalamus in the brain senses stress and signals the pituitary gland, which then tells the adrenal glands to release cortisol. Now cortisol for long as been seen as the enemy but it is actually needed for adequate function of many systems in the body. Cortisol helps the body mobilize energy, regulate blood sugar, maintain blood pressure, and respond to threats.
In a healthy rhythm, cortisol rises sharply in the morning to help you wake up and then slowly declines throughout the day so the body can wind down in the evening. This pattern is called the diurnal cortisol rhythm, and it is one of the most important hormonal rhythms in the body.
But when stress becomes chronic, this system can start to malfunction. The signals between the brain and the adrenal glands become dysregulated, and cortisol patterns shift. This is what we refer to as HPA axis dysfunction.
When this happens, the symptoms are often subtle at first but become increasingly disruptive over time. People may experience fatigue that sleep doesn’t fix, brain fog, anxiety, poor stress tolerance, sleep disturbances, blood sugar swings, and hormonal imbalances. Some people feel wired and anxious all the time, while others feel flat, depleted, and unable to handle even small stressors.
Understanding what phase of HPA axis dysfunction someone is in is important because different interventions are helpful at different stages. This is where adaptogens come into the conversation.
Adaptogens are a group of herbs that help the body regulate its stress response. Instead of pushing hormones in one direction, they work by helping the body adapt to stress and restore balance in the neuroendocrine system.
But not all adaptogens do the same thing, and using the wrong one at the wrong time can actually make symptoms worse.
The High Cortisol Phase
In the early stages of chronic stress, the body often produces too much cortisol. The stress response system is overactive, and the nervous system remains in a constant state of alert. This phase often shows up as anxiety, insomnia, irritability, racing thoughts, and difficulty relaxing. Cortisol may be elevated at night, making it hard to fall asleep or stay asleep.
I remember back when I was in this phase I was always hungry, felt puffy, gained about 15 pounds and was nervous almost all the time. In this phase, the goal is not to stimulate the stress system further. Instead, we want to calm it.
Adaptogens that work well here include ashwagandha, holy basil, and phosphatidylserine-supportive herbs.
Ashwagandha is one of the most studied adaptogens for stress regulation. It works by lowering excessive cortisol signaling and supporting GABA activity in the brain, which promotes a calmer nervous system. It is especially helpful for people who feel anxious, overstimulated, or mentally exhausted.
Holy basil, also known as tulsi, has a unique ability to reduce stress-induced inflammation while stabilizing blood sugar and cortisol rhythms. Many people find it particularly helpful when stress is affecting mood and metabolic health.
Phosphatidylserine is a phospholipid that supports brain cell function and helps regulate the body’s stress response by influencing communication within the HPA axis. It is commonly used to lower elevated cortisol, particularly at night, which can help calm the nervous system and improve sleep quality.
These herbs are best used when someone feels wired, overstimulated, or unable to shut their brain off at night.
The Mixed or Dysregulated Phase
Over time, chronic stress can create a more chaotic pattern where cortisol levels fluctuate unpredictably. Some parts of the day may show elevated cortisol, while others show suppressed levels.
People in this phase often feel tired during the day but wired at night. Energy may fluctuate dramatically, and stress tolerance is usually very low. Blood sugar instability, hormone imbalances, and digestive issues are common in this stage.
Adaptogens that help stabilize the system in this phase include rhodiola, eleuthero, and schisandra.
Rhodiola rosea is known for its ability to improve resilience to both mental and physical stress. It works by modulating stress signaling in the brain and improving mitochondrial energy production. This makes it particularly useful for people experiencing mental fatigue, poor concentration, and burnout.
Eleuthero, sometimes called Siberian ginseng, helps improve endurance and resilience without overstimulating the nervous system. It supports the adrenal glands and improves the body’s ability to handle ongoing stressors.
Schisandra is often overlooked but extremely powerful. It supports the liver, nervous system, and endocrine system simultaneously. It also enhances stress resilience while protecting against oxidative stress.
These adaptogens are helpful when someone feels unpredictably tired, mentally foggy, and unable to handle stress the way they used to.
The Low Cortisol Phase
After long periods of chronic stress, the body can eventually reach a point where cortisol production becomes blunted or insufficient. This stage is sometimes referred to as adrenal downregulation or hypocortisolism.
The symptoms here tend to look very different from the earlier stages. People often feel extremely fatigued, struggle to get out of bed in the morning, and experience dizziness, low blood pressure, and difficulty handling even mild stress. This phase is what began my journey into healing myself. I remember not being able to get out of bed, everything seemed like the end of the world, I would eat and be hungry trying not to pass out in my chair right after, and not to mention the numerous times I fainted from standing up too fast… embarrasing).
Morning cortisol is often low in this phase, which means the body struggles to generate the energy needed to start the day.
In this stage, the goal is to support and gently stimulate cortisol signaling.
Adaptogens that are useful here include licorice root, rhodiola in low doses, and ginseng species like panax ginseng.
Licorice root is particularly interesting because it slows the breakdown of cortisol in the body. This allows cortisol to stay active longer, effectively amplifying the body’s existing cortisol levels. For people with low morning cortisol, this can significantly improve energy and blood pressure.
Panax ginseng helps support adrenal signaling and improves both cognitive and physical performance. It is one of the stronger adaptogens, so it is typically used when someone is clearly depleted rather than overstimulated.
These herbs are most appropriate when someone feels profoundly fatigued, weak under stress, and unable to maintain energy throughout the day.
Why Adaptogens Work
Adaptogens are fascinating because they don’t function like stimulants or sedatives. Instead, they influence the signaling pathways that regulate stress hormones, inflammation, and cellular energy production.
Many adaptogens interact with the hypothalamus and pituitary glands, which are the control centers of the HPA axis. By influencing these signals, adaptogens help the body recalibrate how it responds to stress.
They also support mitochondrial function, reduce oxidative stress, and improve the body’s resilience to both psychological and physical challenges.
In other words, adaptogens are not simply about increasing or decreasing cortisol. They are about helping the body respond to stress more intelligently.
The Bigger Picture
While adaptogens can be incredibly helpful, they are rarely the entire solution. HPA axis dysfunction is almost always influenced by other factors such as poor sleep, blood sugar instability, inflammation, gut health imbalances, and chronic psychological stress.
Supporting the stress response system usually requires a broader approach that includes circadian rhythm regulation, nutrient sufficiency, stable blood sugar, and nervous system support. Adaptogens are simply one of the tools that can help guide the body back toward balance.
And when used correctly, at the correct times, they can be surprisingly powerful.