Neurochemicals 101: Your Guide to the Big 5 That Run Your Body
"The mind and body are not separate. What affects one, affects the other."
—Dr. Candace Pert
Neurochemicals are powerful chemical messengers that influence every aspect of our lives, from mood and energy levels to stress management and social interactions. This article covers the essential neurochemicals—dopamine, cortisol, serotonin, endorphins, and oxytocin—providing insights into their roles, evolutionary purposes, symptoms of imbalance, practical ways to optimize them, key scientific stats, and common myths.
Neurochemicals 101: The Big 5
1. Dopamine
Dopamine is a catecholamine neurotransmitter best known not for triggering pleasure, but for driving motivation, anticipation, and goal pursuit. Produced in the substantia nigra and ventral tegmental area (VTA), dopamine helps reinforce behavior through a reward prediction system that spikes when outcomes exceed expectations and dips when they don’t.
Rather than reacting to pleasure itself, dopamine ramps up in anticipation—before eating, achieving, or taking action, not during. This role in drive and behavior was made especially clear in a striking 1997 experiment, where researchers genetically engineered mice to lack dopamine entirely. The animals lost all motivation to eat and eventually starved to death, even though they were physically capable of eating.
This is also the reason “the feast is in the first bite,” as they say, and the reason we scroll endlessly, chase novelty, or crave another hit of stimulation (that Amazon package, that new car, that raise) before the first has even worn off.
Disruptions in dopamine signaling are linked to conditions like Parkinson’s disease, ADHD, and addiction, where motivation and reward processing break down.
Not the Whole Story
Myth: Dopamine is solely a "pleasure chemical."
Reality: It is primarily associated with motivation and the pursuit of rewards, not the pleasure itself.
Roles in Health and Mood:
Drives goal-directed behavior.
Improves mood, focus, and motivation.
Evolutionary Role: Historically, motivated humans to seek resources, ensuring survival through goal-oriented behavior like hunting and gathering. This drive-based system rewarded effort and persistence, reinforcing actions that led to food, shelter, and social connection in uncertain environments.
Modern Mismatch: Our brains evolved to seek out rewarding experiences in environments that were far less stimulating than the world we live in today. Now, hyper-palatable processed foods, endless social media scrolls, and digital feedback loops hijack our dopamine pathways, leading to compulsive behaviors, reward desensitization, and a drop in motivation for slower, healthier activities. Scientists and tech designers understand these dopaminergic systems well and have learned how to exploit them through the exact pitch of a snack’s crunch, the perfect ratio of salt to fat, the color and timing of app notifications, and even the micro-animation of a “Like” button.
Symptoms of Imbalance:
Low: Fatigue, lack of motivation, mood swings, difficulty concentrating.
High: Addiction, risk-taking, impulsiveness.
How to Optimize:
Chase mastery, not micro-rewards: Set long-term goals and break them into smaller wins. The anticipation of progress, not the outcome, is what drives dopamine most.
Delay the hit: Practice intentional discomfort like waiting 10 minutes before checking your phone or delaying a snack. This strengthens your ability to regulate cravings and delay gratification.
Delete the slot machine in your pocket: Cut out infinite-scroll apps and remove unnecessary notifications.
Meditate with a challenge: Try single-point focus meditation (like breath-holding, candle gazing, or mantra) to enhance baseline dopamine and executive control.
Seek out controlled discomfort: Lean into hormetic stressors like cold plunges, fasting, or intense workouts. These build your tolerance to discomfort and help rebalance your dopamine set point, which modern life constantly overwhelms.
Cold showers or ice baths spike dopamine up to 250%, and it stays elevated for hours. It’s one of the cleanest, most sustainable hits you can get. This is what I use.
Exercise, especially when it’s effortful or novel, raises baseline dopamine and improves receptor sensitivity over time. The harder it feels in the moment, the more rewarding it is afterward. Make it hard, make it varied, get rewarded.
Fasting increases dopamine receptor sensitivity and upregulates baseline dopamine over time. This is because when our ancestors went without food, their brains adapted by becoming more alert, motivated, and goal-driven to improve their chances of survival. Fasting is an ancient, adaptive system that rewards focus and persistence when resources are scarce.
The sauna not only improves circulation and reduces inflammation, but it also boosts endorphins and activates the dopamine system. Plus, regular heat exposure is linked to improved mood, resilience, and even a lower risk of depression.. It feels good afterward because it was hard during. That’s the dopamine sweet spot. This is what I use.
Do hard things—on purpose: Whether it’s waking up early, going for a walk without music, or reading instead of scrolling, embracing effort over ease helps recalibrate your reward system. The more we avoid discomfort, the more enslaved we become to it.
Watch for 'pleasure creep': When something that used to feel good (like a walk, a snack, or a show) no longer feels satisfying, it's a sign your brain's reward system may be overloaded. Instead of chasing more, pause and reset.
Recognize that craving is pain: That restless urge to check your phone, snack, or buy something isn’t harmless—it’s a micro-dose of pain driving you toward the next hit. Learning to sit with the urge, without acting on it, is a practice that strengthens your resilience and self-control.
Want to learn more about this powerful molecule? I highly recommend the book, Dopamine Nation.
2. Cortisol
Cortisol is often called the body’s “stress hormone,” but that’s only part of the story. It’s a powerful glucocorticoid produced by the adrenal glands that helps regulate energy, inflammation, blood pressure, and our circadian rhythm. In short bursts, it’s adaptive, helping you wake up, focus, or respond to danger. But when cortisol stays elevated due to chronic stress, it starts to backfire, increasing the risk of heart disease, sleep problems, weight gain, and cognitive decline.
One landmark study published in Neurology found that people with higher cortisol levels in midlife had smaller brain volumes and worse memory performance later in life, even after adjusting for other health factors. This supports the idea that chronically elevated cortisol doesn’t just wear down the body—it also accelerates brain aging. It's the hormone that makes modern life feel overwhelming when left unchecked.
Not the Whole Story
Myth: Cortisol is always harmful.
Reality: Cortisol gets a bad wrap, but it is essential for waking up, regulating blood sugar, and managing acute stress—it’s chronic elevation that causes harm.
Roles in Health and Mood:
Regulates metabolism and inflammation.
Enhances alertness in stressful situations.
Evolutionary Role: Enabled quick reactions in dangerous environments, facilitating the classic fight-or-flight response. This rapid mobilization of energy and focus helped early humans escape predators, respond to threats, and survive in unpredictable, high-stress settings.
Modern Mismatch: Constant exposure to modern stressors—work deadlines, financial strain, overstimulation—keeps cortisol chronically elevated, disrupting your body’s natural rhythms. Over time, this hijacks your sleep, dampens immunity, and shrinks brain regions like the hippocampus, which is critical for memory and mood regulation. What was once a short-term survival hormone has become a long-term health liability in the modern world.
Symptoms of Imbalance:
High: Anxiety, insomnia, weight gain, immune dysfunction.
Low: Fatigue, depression, low blood pressure.
How to Optimize:
Front-load your stress: Do your most demanding work or workouts earlier in the day, when cortisol is naturally elevated. This aligns with your circadian rhythm and helps avoid sleep disruption at night.
Get early morning sunlight: Sunlight within 30 to 60 minutes of waking helps anchor your circadian rhythm, triggering a healthy cortisol pulse in the morning and supporting melatonin release at night. Even on cloudy days, natural light beats indoor bulbs.
Cut the late-night stimulation: Bright lights, email checks, doomscrolling, and evening caffeine all keep cortisol artificially high when it should be winding down. Blue light, in particular, suppresses melatonin and delays cortisol’s decline.
Create a cortisol “off-ramp”: You need a ritual to shift from high-alert to rest mode. Try breathwork, journaling, a hot shower, or magnesium before bed to downshift your nervous system and signal safety.
Lift weights, but not too late: Strength training boosts cortisol temporarily, but over time improves your body’s ability to regulate stress. Just don’t crush legs at 8 p.m. since late-night intensity can throw off your sleep.
Prioritize sleep like it’s a prescription: Poor sleep raises baseline cortisol and sets the stage for insulin resistance, mood swings, and brain fog. Aim for 7 to 9 hours, and protect your wind-down time like you would a workout.
Learn to “complete the stress cycle”: According to research by Emily and Amelia Nagoski, the stress response is a physical cycle, and to close it, you need to move. Even a brisk walk or five minutes of dancing can signal to your body that the threat is over.
Limit your noise exposure: Our ancestors rarely encountered sound levels above 30 to 40 decibels. Today, even walking into a restaurant exposes you to 80 decibels or more, not to mention traffic, tools like lawn mowers, and the volume of your headphones or car speakers. Chronic noise activates the stress response and keeps cortisol elevated.
Avoid excessive news consumption: Most headlines are designed to trigger emotional arousal—fear, outrage, or urgency. Repeated exposure to this kind of input keeps your nervous system on high alert. Skimming headlines once a day is enough. Your cortisol will thank you.
3. Serotonin
You’ve probably heard serotonin called the “happiness chemical,” but that’s only part of the story. This powerful neurotransmitter acts more like a regulator—keeping mood, digestion, sleep, and cognition in balance. While 90% of serotonin is made in the gut, its effects are felt system-wide, influencing everything from your appetite to your emotional resilience. Low levels are consistently linked to increased rates of depression, anxiety, and poor sleep, but optimal serotonin isn’t about being blissfully happy, it’s about feeling calm, stable, and grounded. When serotonin is steady, so are you.
Not the Whole Story
Myth: Serotonin deficiency alone causes depression.
Reality: Depression is multifactorial; serotonin plays a role, but so do lifestyle, trauma, inflammation, and neuroplasticity.
Roles in Health and Mood:
Stabilizes mood and promotes feelings of well-being.
Supports digestion and sleep cycles.
Evolutionary Role: Promoted social bonding and community cohesion, increasing survival odds through group living. Higher serotonin levels reinforced prosocial behaviors like cooperation and empathy, which helped early humans form alliances and navigate complex social hierarchies.
Modern Mismatch: In our ancestral environment, serotonin thrived on things like sunshine, physical movement, real food, and face-to-face connection—conditions that signaled safety and social belonging. Today, we scroll in solitude, eat ultra-processed diets that disrupt the gut, and sit under artificial light for most of the day. The result? The same system designed to foster calm and social harmony is left undernourished and overstimulated in the wrong ways. We're biologically wired for community and movement, yet we live in a world that often deprives us of both. It’s no surprise that rates of anxiety and depression are on the rise when serotonin’s natural triggers are increasingly absent.
Symptoms of Imbalance:
Low: Depression, anxiety, insomnia, irritability.
High: Restlessness, confusion, rapid heart rate (rare, usually medication-induced).
How to Optimize:
Get 20+ minutes of sun exposure each morning.
Exercise regularly, especially aerobic workouts and yoga.
Eat foods high in tryptophan (e.g., turkey, salmon, eggs, pumpkin seeds).
Cultivate supportive relationships, gratitude, and volunteering.
Avoid chronic stress and get consistent, quality sleep.
4. Endorphins
You’ve probably felt that euphoric “runner’s high” or the deep calm after a belly laugh—those are endorphins at work. These powerful, opioid-like neuropeptides are your brain’s built-in painkillers, released during physical exertion, stress, laughter, or even music. Endorphins don’t just dull pain; they elevate mood, increase pleasure, and help you push through both physical and emotional stressors.
In one study, researchers used PET imaging to show that vigorous aerobic exercise led to a greater increase in endorphin binding in areas of the brain responsible for emotional regulation and pain control compared to aerobic exercise. Another study found that just 15 minutes of laughter significantly raised endorphin levels, improving both pain tolerance and mood.
Not the Whole Story
Myth: Endorphins alone cause “runner’s high.”
Reality: Endocannabinoids likely play a more dominant role; endorphins help but don’t cross the blood-brain barrier easily.
Roles in Health and Mood:
Alleviate pain and stress.
Elevate mood, often leading to a sense of euphoria. Improved resilience.
Evolutionary Role: Endorphins helped early humans endure physical hardship, reduce pain during injury or childbirth, and sustain effort through long hunts or migrations, making survival under pressure more feasible. These endogenous opioids acted as built-in painkillers and mood boosters during intense physical effort.
Modern Mismatch: In a world of climate control, cushioned shoes, and chairs on every corner, most people rarely push their physical limits. This lack of natural stress exposure means we miss the regular endorphin surges our ancestors experienced. Without these built-in chemical rewards, our resilience drops, and minor stressors can feel overwhelming.
Symptoms of Imbalance:
Low: Increased sensitivity to pain, mood swings, anxiety.
High: Rare naturally; associated with thrill-seeking or addictive behaviors.
How to Optimize:
Get Moving: Engage in high-intensity or sustained moderate exercise like running, swimming, or cycling—these trigger strong endorphin release, often referred to as the “runner’s high.”
Laugh Daily: Genuine laughter activates brain regions associated with endorphin production. Watch a comedy, call a funny friend, or just embrace playfulness more often.
Listen to Music: Music—especially the kind that gives you chills—can stimulate endorphin release and boost your pain tolerance. For me, this is music that involves multiple singers singing in unison, emotionally charged crescendos, and powerful harmonic layering that hits you in the chest.
Get Acupuncture or Massage: Both have been shown to increase circulating endorphin levels and decrease stress-related pain responses.'
Use Cold or Heat Exposure: Cold plunges and saunas all stimulate endorphin release as the body adapts to temporary discomfort.
Eat Spicy Foods: Capsaicin, the compound in chili peppers, can trigger mild pain signals that stimulate an endorphin release response.
Lean into Challenge: Endorphins are released in response to overcoming discomfort. Regularly exposing yourself to physical or mental stressors (like endurance workouts, difficult hikes, or cold exposure) helps condition your body to adapt with a calming chemical counterbalance.
5. Oxytocin
You’ve likely heard oxytocin called the “love hormone,” but it’s more than just a feel-good chemical. Oxytocin is the biological glue of human connection—deeply involved in trust, bonding, and emotional safety. It’s released during eye contact, physical touch, and shared experiences, helping us build social ties that historically meant the difference between survival and isolation.
One compelling study from PNAS showed that intranasal oxytocin significantly increased trust in participants during a financial risk game, even when there was a possibility of betrayal. This suggests oxytocin doesn’t just make us feel good—it shapes how we relate to others, especially in uncertain social situations.
Not the Whole Story
Myth: Oxytocin always promotes positive outcomes.
Reality: While it enhances bonding, it can also increase in-group favoritism and out-group distrust.
Roles in Health and Mood:
Facilitates bonding between mothers and infants, partners, and social groups.
Promotes trust, empathy, and reduces stress.
Evolutionary Role: Ensured group cohesion and increased offspring survival through strengthened social bonds. Oxytocin reinforced caregiving behaviors and trust within tribes, increasing chances of survival in harsh environments.
Modern Mismatch: Increased digital interactions and decreased physical contact lead to lower oxytocin levels, affecting mental health and social stability. We scroll instead of connecting, text instead of touching, and swipe instead of speaking face-to-face. This lack of embodied social interaction reduces the micro-moments of connection that once kept stress in check. Over time, this deficit can lead to increased feelings of loneliness, distrust, and emotional dysregulation.
Symptoms of Imbalance:
Low: Loneliness, depression, social anxiety.
High: Rare, but excessive bonding or trust that might lead to dependency.
How to Optimize:
Prioritize physical touch: Hugs, hand-holding, massage, and even light touch can all trigger oxytocin release and lower stress.
Make eye contact during conversation: Sustained, genuine eye contact boosts feelings of trust and connection, key triggers for oxytocin.
Spend time with people you care about: Shared experiences, laughter, and emotionally safe environments promote stronger oxytocin signaling.
Express gratitude often: Saying “thank you” and showing appreciation builds social trust and deepens emotional bonds.
Engage in group rituals: Activities like communal meals, singing, prayer, or even synchronized movement (like group workouts or dance) enhance group cohesion and oxytocin levels.
Practice active listening: Being fully present and attentive during conversation creates emotional safety and encourages oxytocin release in both people.
Limit digital-only interactions: Prioritize face-to-face or voice conversations when possible to strengthen real-world connection pathways.
Hang out with pets: Bonding with animals can increase oxytocin and reduce stress.
My Take
Each of these big five neurochemicals plays a central role in how we move through the world: from getting up in the morning to connecting with others or bouncing back from a tough day. And the truth is, our modern lifestyle is completely mismatched with the systems we evolved to thrive in.
When I started learning how to support these systems through things like sunlight, movement, and connection, I noticed everything got easier: better energy, clearer thinking, more resilience. I also realized that I was in control of my body and the messengers within it, not the other way around.
You don’t need a supplement stack or lab panel to start optimizing your hormones and biological systems. You just need to show up daily for the basics that actually work. These five are a great place to start.
Let your biology work for you, not against you.
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