By Avni Dalal, ND
If you're constantly hitting snooze, relying on caffeine to get through the afternoon, or feeling wired at night when it’s time to wind down, your body may be trying to tell you something. One potential culprit behind low energy and disrupted sleep patterns to consider? An imbalanced cortisol curve.
Let’s take a deeper look at how cortisol—the body’s primary stress hormone—affects energy and why optimizing your natural cortisol rhythm may be the key to reclaiming your life back.
What Is Cortisol and Why Does It Matter?
Cortisol is a hormone produced by the adrenal glands in response to stress. It plays a vital role in maintaining homeostasis by helping to regulate blood sugar, blood pressure, immune function, and inflammation and—most notably—can affect your sleep-wake cycle, also known as the circadian rhythm.1
Under healthy conditions, cortisol follows a predictable daily pattern:
- It peaks in the morning (typically 30–45 minutes after waking), helping you feel alert and ready for the day. This is known as the cortisol awakening response (CAR).1,2
- It gradually declines throughout the day into the evening, reaching its lowest point at the early part of night to allow for restful sleep.2
This pattern is often referred to as the diurnal cortisol curve. This pattern of cortisol secretion is primarily regulated by the hypothalamic-pituitary-adrenal (HPA) axis and is influenced by the central circadian pacemaker located in our hypothalamus.1 When this rhythm is disrupted—due to chronic stressors, poor sleep, irregular eating patterns, or other lifestyle factors—it can lead to a host of energy-related complaints.
Signs Your Cortisol Curve May Be off
While cortisol levels can vary slightly from person to person, certain symptoms may signal an imbalance in your natural cortisol rhythm:
- Morning fatigue or difficulty waking due to persistent tiredness, energy crashes in the afternoon, and a general feeling of unwellness3,4
- Increased cravings for sugar or caffeine and unintentional weight gain or weight loss due to changes in appetite3,4
- Feeling "tired but wired" at night and trouble falling or staying asleep, contributing to overall poor sleep quality3
- Brain fog, mood changes, and other impacts on cognition such as issues with memory and attention5,6
- Muscle and joint pain flares caused by abnormal levels of cortisol3
- Nausea and abdominal pain3,4
It’s important to note that these symptoms don’t necessarily mean you have a medical condition, but they could be a sign that your circadian cortisol rhythm is suboptimal and is affecting your energy regulation and stress response.
What Causes Cortisol Imbalance?
Several lifestyle and environmental factors can disrupt cortisol production and timing:
- Chronic stress: Whether it's emotional, physical, or environmental, prolonged stress signals the adrenal glands to sustain activation of the HPA axis, resulting in persistently elevated cortisol levels, which can flatten the diurnal rhythm.7
- Poor sleep hygiene: Inconsistent sleep schedules, screen time before bed, inadequate rest, and conditions like insomnia can alter the cortisol cycle.8
- Psychological disorders, such as major depressive disorder, are also associated with HPA axis hyperactivity and altered cortisol patterns, including a blunted CAR and a flattened diurnal curve.9
- Chronic conditions, like type 2 diabetes mellitus and certain neurodegenerative conditions, are linked to cortisol dysregulation due to HPA axis dysfunction and issues with the inflammatory response.7,9
- Shift work or jet lag: Irregular exposure to light and altered sleep-wake cycles can misalign cortisol production.10
How to Support a Healthy Cortisol Curve
Optimizing your energy levels may start with supporting your body’s natural cortisol rhythm. Here are a few science-backed strategies to help restore that balance so you feel more energized during the day and ready to rest in the evenings:
1. Prioritize Consistent Sleep and Wake Times
Aim to go to bed and wake up at the same time each day—even on weekends. Exposure to morning sunlight within 30 minutes of waking can help regulate your circadian rhythm.
2. Balance Blood Sugar Levels
Eat balanced meals with protein, healthy fats, and complex carbohydrates. Avoid skipping meals or relying on sugar or caffeine to power through the day.
3. Practice Stress Management Techniques
Mindfulness, meditation, deep breathing, and light movement like yoga or walking can help your body recover from chronic stress.
4. Reduce Evening Stimulation
Avoid screens, intense workouts, and large meals late in the evening. Creating a calming nighttime routine helps signal the body to begin winding down.
5. Adaptogenic Herbs and Nutritional Support
Some individuals choose to incorporate lifestyle-focused supplements—such as adaptogenic herbs like Ashwagandha, rhodiola, or eleuthero—to support stress resilience. However, it’s best to consult a qualified healthcare provider before beginning any new supplement routine.
When to Seek Professional Guidance
If you're experiencing ongoing fatigue or suspect your cortisol rhythm may be out of balance, specialized lab testing—such as salivary or dried urine cortisol assessments—can offer insights into your diurnal cortisol curve. Healthcare providers trained in functional or integrative approaches can help interpret these results, offer personalized support strategies, and conduct further work-up if other issues are at play.
Summary
If you’ve been struggling with low energy, don’t underestimate the impact of your cortisol rhythm. While cortisol is often labeled as a “stress hormone,” it plays a vital role in maintaining energy, mood, cognition, and metabolic health. Small daily habits—like managing stress, getting quality sleep, and eating balanced meals—can go a long way in supporting a healthy cortisol curve and helping you feel your best throughout the day.
References:
1. Oster H et al. Endocr Rev. 2017;38(1):3-45.
2. Stalder T et al. Endocr Rev. 2025;46(1):43-59.
3. Beuschlein F et al. J Clin Endocrinol Metab. 2024;109(7):1657-1683.
4. Bornstein SR et al. J Clin Endocrinol Metab. 2016;101(2):364-389.
5. Kalafatakis K et al. Proc Natl Acad Sci U S A. 2018;115(17):E4091-E4100.
6. Charles ST et al. Psychoneuroendocrinology. 2020;112:104516.
7. Knezevic E et al. Cells. 2023;12(23):2726.
8. Balbo M et al. Int J Endocrinol. 2010;2010:759234.
9. Joseph JJ et al. Ann N Y Acad Sci. 2017;1391(1):20-34.
10. Minnetti M et al. J Endocrinol. 2020;246(2):R13-R31.
