When most people think of hormones, they usually don’t think of their brain. The thing about hormones that we often don’t realize is that they are involved in a complex symphony of biochemical reactions in virtually every tissue in our bodies. The health and function of the brain are deeply dependent on hormones. When hormone levels change throughout our lives, it impacts our brain’s structure and function immensely. Here is a breakdown of the role of certain hormones in the brain and how to maintain functional levels in your body.
What are hormones?
Hormones are chemical messengers produced by certain tissues in the body that act on other tissues of the body. They travel through the bloodstream to coordinate physiology — metabolism, growth, reproduction, mood, immunity, repair, and more. Hormones are an important part of the body’s metabolism for homeostasis but fluctuations in the production and function of hormones can lead to a cascade of unwanted symptoms.
A great example of this is insulin. Insulin is needed for our body to use glucose to make energy. When the pancreas can’t make enough insulin, such as in a person with Type 1 diabetes, the glucose can’t be taken into cells for energy. Instead, levels of glucose rise in the blood, which can lead to diabetic ketoacidosis and even death. The following section will review some of the hormones that are essential for our brains to function properly.
Hormones Needed for Brain Health
1. Thyroid Hormones (T3 and T4)
Role: Thyroid hormones regulate brain energy metabolism, myelination (nerve insulation), and neurotransmitter balance.
Symptoms of Low Thyroid Hormones: Low thyroid hormone causes fatigue, brain fog, poor memory, and low mood.
Symptoms of High Thyroid Hormones: When thyroid hormone levels are too high, people often experience anxiety, irritability, and sleep problems.
Thyroid hormone can be elevated (hyperthyroid) or too low (hypothyroid). Conditions affecting thyroid hormones are common and on the rise per epidemiological data. Testing and regulating your thyroid hormone levels is a baseline strategy for brain function since we know T3 (triiodothyronine) directly affects neuronal function and synaptic activity. These conditions can be treated so getting your thyroid hormone levels checked at your yearly check-up is an easy way to avoid cognitive and mood symptoms.
2. Estrogen
Role: Estrogen protects neurons from oxidative stress, enhances blood flow, and promotes the growth of new synapses. Estrogen also supports serotonin, acetylcholine, and dopamine systems — crucial for learning, memory, and mood.
Low estrogen ( Caused by things like menopause, very low levels of body fat, and chronic stress) leads to brain fog, mood swings, and memory decline.
Both men and women have estrogen in their bodies, but women tend to have more fluctuations in estrogen levels which can manifest as changes in brain function. Research supports hormone replacement therapy for menopausal women to protect the brain, cardiovascular system and bone density. There are estrogen receptors throughout the brain. When levels of estrogen drop, many women experience brain fog and mood changes. It has been shown that Estradiol (E2) is the most neuroprotective form and can be safely used in appropriate doses to avoid neurodegeneration as women age.
3. Progesterone
Role: Progesterone calms the nervous system and promotes sleep via GABA receptor activation (your main “relaxation” pathway). Progesterone also supports myelin formation and reduces neuroinflammation.
Symptoms of low Progesterone: anxiety, insomnia, and irritability.
Optimizing progesterone levels when low can improve quality of life in people. Often sleep and mood improve when progesterone levels improve. When we can have good quality sleep, our brains are able to repair damage and process what we have learned or experienced throughout the day. Sleep is also good for overall metabolism and maintaining a healthy weight. Women can work with a well-trained healthcare practitioner to assess their hormone levels and replace hormones if levels are too low. Check out my blog entry on sleep and metabolism to learn more about how important sleep is for our health.
4. Testosterone
Role: Testosterone supports motivation, focus, spatial memory, and resilience to stress. Adequate testosterone promotes dopamine activity, which drives reward and mental clarity in both men and women.
Symptoms of low Testosterone: Low testosterone causes brain fog, low drive, low libido and depression.
Optimizing testosterone levels is not only for men; women benefit from functional levels based on their body’s needs as well. It is important to work with a healthcare provider who provides the correct dose so as not to overdose testosterone since this can lead to other unwanted side effects and chronic health conditions. Testosterone often declines with age. If you feel any symptoms associated with low testosterone, speak with your healthcare provider about checking your testosterone levels to determine if testosterone replacement will be helpful for you.
5. Cortisol
Role: Cortisol regulates stress response, energy availability, and circadian rhythm.
Healthy cortisol rhythm: high in morning (promotes alertness), low at night (to induce sleep and rest).
Chronically high cortisol symptoms: Causes hippocampal shrinkage, poor memory, anxiety, and sleep disruption.
Symptoms of too low cortisol: Insufficient cortisol results in low motivation, brain fog, and poor focus.
Cortisol, also known as the “stress hormone” is very important in the body. We need certain amounts throughout the day to keep us functioning but when levels are chronically high or chronically low, our brain is affected as well as most body systems. Cortisol levels can be tested and managed with lifestyle changes, certain supplements and pharmaceuticals in some cases.
6. Insulin
Role: Insulin is needed for neurons in the brain to take up glucose (their main fuel).
Insulin resistance in the brain is a metabolic condition in which cells are no longer able to accept glucose from insulin causing higher circulating glucose levels along with an energy deficit in the brain because the insulin unable to shuttle glucose into cells for energy production. Insulin resistance in the brain has been called “type 3 diabetes” and linked to Alzheimer’s disease.
Insulin levels reflect our metabolic health. When insulin levels are normal, this yields a stable energy source for brain function. If Insulin levels are too high, this correlates with high blood glucose levels and insulin resistance.
There is now an epidemic of what is called insulin resistance in America due to our diets high in sugars and processed foods along with physical inactivity and weight gain. Cells become numb to insulin requiring much more to be produced but glucose is still unable to get into cells eventually leading to type 2 diabetes. Insulin resistance can be reversed with balanced meals comprised of whole, natural foods and daily physical activity. An easy way to support your insulin function by taking a 20-minute walk after meals.
7. Melatonin
Role: Melatonin regulates sleep–wake cycles and protects neurons through antioxidant effects. Melatonin is synthesized from another hormone, serotonin, in the pineal gland.
Low melatonin Symptoms: poor sleep, oxidative stress, and impaired memory consolidation.
Melatonin is a hormone produced by the pineal gland at night in response to darkness.
It helps regulate circadian rhythm (your sleep–wake cycle), antioxidant defense, and aspects of immune and mitochondrial function.
Small amounts of melatonin can be supplemented to support sleep but even the lowest dose at the store is many times more than what we produce naturally. While melatonin is generally considered safe, especially at low doses and for short-term use, it can pose risks in certain situations or with long-term, high-dose supplementation. If you want to regulate circadian rhythm and melatonin production in your brain, getting sunlight exposure by looking at sky when the sun is setting can trigger your pineal gland to start making melatonin to prepare for sleep. Avoid bright lighting at home as well as excessive blue light exposure from electronics to maintain healthy levels of melatonin and promote sleep. Help your brain wake up in the morning by exposing your eyes to morning sunlight for a few minutes to signal your brain that it is time to start your day.
8. Oxytocin
Role: Oxytocin is known as the “connection hormone.” It enhances empathy, bonding, and social memory. Oxytocin promotes calmness and counters stress hormone effects. Oxytocin is a hormone that is expressed when we are connecting with others. Mothers and babies produce oxytocin during breastfeeding. Oxytocin is also released during sexual arousal and climax promoting bonding, relaxation and trust afterwards. Oxytocin also helps counteract cortisol (the stress hormone) reducing anxiety and promoting a restful and relaxed state. Oxytocin secretion follows a daily rhythm, with slightly higher expression in the evening and nighttime, promoting calmness and sleep readiness. There is promising research utilizing oxytocin to treat autism spectrum disorder, anxiety, PTSD, depression, chronic pain, and addiction. More research is needed to determine the potential uses for oxytocin as a therapeutic substance. Oxytocin levels are naturally boosted by physical touch, laughter, and trust-building relationships.
9. Growth Hormone (GH) & IGF-1
Role: Growth hormone supports brain repair, neurogenesis, and myelin formation. Growth hormone (GH) and Insulin-like Growth Factor 1 (IGF-1) both support neural growth, repair, cognition, mood, and resilience. IGF-1 supports the formation of neural stem cells, especially in the hippocampus, a key region for learning and memory.
IGF-1 enhances the survival of newly formed neurons by preventing cell death known as apoptosis. Both GH and IGF-1 decline with age and deficiency contributes to slower thinking, mood changes, and reduced neuroplasticity which slows brain recovery. In some cases, GH can be increased with daily injections to raise levels in the body. This therapy should be closely monitored by a healthcare professional. There are also peptide therapies available to stimulate production of GH in the body. Natural ways to increase GH production include fasting, exercise and adequate sleep because GH surges during deep sleep, one of many reasons sleep is critical for brain regeneration.
10. DHEA (dehydroepiandrosterone)
Role: DHEA supports cognitive function via hormone regulation, acts as an anti-inflammatory and regulates mood and stress response.
DHEA is often called the “neurosteroid” because it is produced not only by the adrenal glands but also within the brain itself (by neurons and glial cells). It plays multiple roles in cognition, mood regulation, neuroprotection, and hormone balance. DHEA levels naturally decline after age 25–30 (this reduction in adrenal hormone production is called“adrenopause”). Lower DHEA is associated with reduced executive function and memory as well as increased risk of dementia. DHEA is sold as an over-the-counter supplement but it is best to work with a healthcare practitioner that can monitor your DHEA levels and recommend the correct dose for you.
Natural Ways to Support Hormone Production
Healthy lifestyle habits support hormone levels. Getting adequate sleep is important for all body systems. Try to prioritize your sleep by going to bed at the same time each night so you are able to get 7-8 hours of quality sleep. Implement a night time routine to ease you into sleep that does not include screen time on your phone or other devices.
Exercise is also helpful in supporting healthy hormone levels. Set aside 30 minutes a day to go for a brisk walk and include some resistance exercises to build strength 2-3 times a week. Exercise is a good stressor on the body but it can also be a bad stress if you are over-training and not allowing enough time to recover.
Be aware of the stressors in your life. Including some stress management techniques in your lifestyle while helping reduce the impact of stress on your health. You can choose a technique that works with your lifestyle whether it is breathing exercises, meditation, prayer, spending time in nature, or listening to happy or calm music. Identify if certain people in your life as toxic or stressful and distance yourself from them if you are able.
Eating a healthy diet consisting of whole foods, plenty of plants and healthy fats can provide you with the nutrients needed to support hormone production. The following table lists the nutrients important for hormonal production and balance. Working with a knowledgeable healthcare practitioner will help you navigate any hormonal changes and also optimize hormone levels as needed.
Top Nutrients That Support Hormones for Brain Function
| Nutrient | Why It Matters for Hormones & Brain | Best Food Sources |
1. Healthy Fats (Omega-3s, Monounsaturated Fats, Cholesterol) | – Hormones like estrogen, progesterone, testosterone, and cortisol are synthesized from cholesterol. – Omega-3s (especially DHA) support neuronal membrane integrity and neurotransmission. | Fatty fish (salmon, sardines), walnuts, flaxseed, olive oil, avocado, pastured eggs |
2. B Vitamins (B6, B12, Folate) | – Crucial for neurotransmitter synthesis (serotonin, dopamine, GABA). – Support estrogen metabolism and methylation. – Deficiencies cause fatigue, anxiety, brain fog. | Leafy greens, lentils, eggs, fish, poultry, nutritional yeast |
| 3.Magnesium | – Involved in >300 enzymatic reactions regulating cortisol, insulin, and thyroid function. – Promotes GABA to calm the nervous system. – Supports progesterone synthesis. | Pumpkin seeds, almonds, spinach, avocado, dark chocolate |
| 4. Zinc | – Needed for thyroid hormone production and testosterone synthesis. – Regulates neuronal communication and synaptic plasticity. – Low levels cause poor focus, mood issues, low libido. | Oysters, pumpkin seeds, cashews, chickpeas, beef |
| 5. Iron | – Required for oxygen transport and dopamine production. – Supports thyroid hormone activation. – Low iron causes fatigue, poor cognition, low mood. | Red meat, lentils, spinach, tofu (with vitamin C) |
| 6. Vitamin D | – Acts as a steroid hormone regulating serotonin gene expression. – Supports estrogen/testosterone balance and mood. – Low D linked to depression and cognitive decline. | Sunlight, salmon, egg yolks, fortified plant milks, supplements |
| 7. Selenium | – Converts inactive T4 → active T3 thyroid hormone. – Antioxidant defense for neurons and endocrine glands. | Brazil nuts, eggs, mushrooms |
| 8. Iodine | – Required for thyroid hormone synthesis, critical for brain metabolism and development. | Seaweed, iodized salt, fish, dairy (if tolerated) |
| 9. Vitamins C & E | – Antioxidant protection for hormone-producing glands (thyroid, adrenals, ovaries). – Reduce oxidative stress and support neuronal resilience. | Citrus fruits, bell peppers, almonds, sunflower seeds, berries |
| 10. Choline | – Precursor for acetylcholine, a neurotransmitter for memory and focus. – Supports methylation for hormone detox and mood regulation. | Eggs, liver, soybeans, cauliflower |
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