Understanding Hormones: Your Body's Chemical Messengers
- Gigi
- 1 day ago
- 6 min read
Have you ever wondered how your body knows when to wake up, when to feel hungry, or how it responds to stress?
The answer lies in remarkable chemical messengers called hormones.
Let's break down the fascinating world of hormone biochemistry in a way that makes sense for everyone.
Hi! Gigi here. If you'r'e chronically online like myself you've likely heard about creating a personal curriculum. Well, I figured it is a trend that is worth my time and decided to give it a go and my assignment is each week (I hope), I will publish a blog post that summarizes the research papers I cover. I hope you join me on this Biochemistry of Women's Health series!
What Are Hormones, Really?
Think of hormones as tiny messages in bottles floating through your bloodstream. Just like a message in a bottle drifting across the ocean, hormones can't choose where they go, they simply travel through your body until they find the right "recipient" (a cell with the matching receptor).
Hormones are chemical signals that travel throughout your entire body (what scientists call "systemic" action). They're different from other signals in your body because they can affect cells far away from where they were made; imagine sending a text message from London that affects someone in Tokyo.
The Numbers Game: Why Quantity Matters
Here's something mind-blowing: if your body released just ONE molecule of a hormone, it would be like throwing one message-in-a-bottle into all the Earth's oceans. The concentration would be so tiny (about 0.35 × 10⁻²⁴ moles per liter, if you're curious) that it couldn't trigger any meaningful response.
That's why your body releases hormones in much larger quantities. For example, cortisol, your "stress hormone" that helps you wake up and handle challenges, circulates at about 0.35 micromoles per litre in the morning.
That's one million million million times more concentrated than our single-molecule example! This massive amplification ensures your body gets the message loud and clear.
Common Hormones You Should Know
Let's meet some of the key players:
Cortisol: The Stress Manager
Often called the "fight-or-flight hormone," cortisol helps you handle stressful situations.
Your levels are highest in the morning (to help you wake up) and lowest at night. It affects everything from your energy levels to your immune system.
Insulin: The Blood Sugar Controller
Made by specialised cells in your pancreas called β-cells (beta cells), insulin helps your body use the sugar from your food.
When insulin signalling doesn't work properly, it can lead to diabetes.
Thyroid Hormones (T3 and T4): The Metabolism Regulators
These hormones control how fast your body burns energy.
They affect your weight, energy levels, body temperature, and even your mood. Interestingly, your thyroid gland makes these hormones using iodine, which is why iodine is added to table salt in many countries.
Sex Hormones (Testosterone, Estrogen, Progesterone)
These steroid hormones govern sexual development, reproduction, and many other processes.
Despite their similar chemical structures, tiny differences make each one unique
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Vitamin D: The Sunshine Hormone
Technically, a hormone despite its name! Your skin produces it when exposed to sunlight. It's crucial for bone health, immune function, and much more.
How Hormones Are Made
The Protein Approach
Hormones like insulin are proteins, which means they're made the same way your body makes any protein:
Your genes provide the recipe (DNA)
That recipe is copied (RNA)
Cellular machinery builds the protein
Additional modifications happen
The finished hormone is packaged for release
For insulin, this is such an intense process that the cells making it can become stressed, which may contribute to some forms of diabetes.
The Cholesterol Connection
Many hormones, including cortisol and sex hormones, are built from cholesterol (yes, the same cholesterol you've heard about in relation to heart health!).
Your body takes cholesterol and modifies it through various chemical reactions to create different hormones, kind of like a sculptor carving different statues from the same block of marble.
The Iodine Innovation
Thyroid hormones are made through a unique process. Your thyroid gland captures iodine from your blood and attaches it to a specific amino acid called tyrosine.
Through some chemical wizardry, two iodine-decorated tyrosines combine to create thyroid hormone. It's chemistry your body performs that would be quite harsh in a laboratory!
The Journey: How Hormones Travel
Once released, hormones travel through your bloodstream. Some can float freely in your blood, while others need special transport proteins (like a taxi service) to help them get around because they don't dissolve well in blood on their own.
Special Shortcuts
Your body has created some clever shortcuts:
The Hypothalamus-Pituitary Connection: These two brain structures are connected by a special blood vessel system called a "portal vein." This means hormones from the hypothalamus reach the pituitary almost undiluted, like having a direct hotline rather than calling through a switchboard.
The Adrenal Highway: Inside your adrenal gland, blood flows directly from the outer layer (which makes cortisol) to the inner layer (which makes adrenaline). This means whenever you get a cortisol spike, you also get an adrenaline rush, explaining why you feel so alert and energised when stressed!
Finding the Target: Hormone Receptors
Hormones only work when they find their specific receptor, think of it as a key finding its lock. There are four main types of hormone receptors:
1. G-Protein-Coupled Receptors (GPCRs)
These sit in cell membranes and are shaped like a bundle of seven helices. When a hormone binds, they activate a complex signaling cascade inside the cell. Many hormones, including adrenaline, use this type.
2. Nuclear Receptors
These receptors work inside cells, often in the nucleus where your DNA lives. Steroid hormones like estrogen and testosterone use these. When the hormone binds, the receptor transforms into a transcription factor that directly affects which genes are turned on or off.
3. Cytokine Receptors
These receptors bring together multiple proteins when activated, creating a signalling platform inside the cell. Growth hormone works this way.
4. Enzyme Receptors
Some receptors are also enzymes. The insulin receptor is the main example. When insulin binds to the outside, the inside part of the receptor activates and triggers a cascade of chemical reactions.
Turning Off the Signal
Just as important as sending a signal is knowing when to stop it. Your body has several strategies:
Kidney Filtration
Your kidneys act like sophisticated filters, removing many hormones and other substances from your blood. They're remarkably good at clearing out anything your body doesn't specifically try to keep.
Liver Processing
Your liver contains enzymes that can modify hormones, usually making them more water-soluble so your kidneys can eliminate them more easily. This is called "biotransformation."
Receptor Recycling
Some receptors, after binding their hormone, get absorbed back into the cell along with the hormone and eventually get broken down. This is called "signalling with appetite."
Protective Degradation
In some cases, your body strategically destroys certain hormones in specific locations. For example, the kidneys break down cortisol to protect mineralocorticoid receptors from being overwhelmed, ensuring the right signal reaches the right receptor.
The Cascade Effect: Signal Amplification
One of the most amazing features of hormone systems is amplification.
Here's how it works using cortisol as an example:
Your brain detects stress (maybe you need to give a presentation)
Your hypothalamus releases tiny amounts of CRH hormone
CRH stimulates your pituitary to release more ACTH hormone
ACTH travels through blood to your adrenal glands
Your adrenal glands release large amounts of cortisol
At each step, the signal gets amplified, like a whisper that becomes a shout. This is why even a small initial signal can create a big bodily response.
Feedback Loops: Staying Balanced
To prevent hormone levels from getting too high, your body uses "negative feedback loops." This is similar to how a thermostat works:
When your house gets warm enough, the thermostat turns off the heater
When thyroid hormone levels get high enough, they signal the pituitary to stop making TSH (thyroid-stimulating hormone)
This keeps hormone levels in a healthy range
Key Takeaways for Your Health
Understanding hormones helps explain many aspects of health:
Morning grogginess? Your cortisol might not be peaking at the right time
Energy crashes after meals? Could be related to insulin sensitivity
Feeling cold all the time? Might be thyroid-related
Mood changes? Multiple hormones influence how you feel
Not sleeping well? Melatonin, cortisol, and other hormones regulate your sleep-wake cycle
The Future of Hormone Research
Scientists are still discovering new signalling molecules in our bodies. Recent research suggests that substances we thought were just metabolic intermediates, like lactate (produced during exercise) or even certain vitamins, might also act as signals.
There's also growing interest in how hormones are released in pulses rather than steadily, and what those patterns might tell us about health and disease.
In Conclusion
Your hormones are sophisticated chemical messengers that coordinate countless processes in your body every second of every day. They travel through your bloodstream like messages in bottles, find their specific targets, trigger precise responses, and then get cleared away when their job is done.
Understanding this system even at a basic level can help you make sense of many health-related terms you encounter and appreciate the remarkable biochemistry happening inside you right now.
Remember: hormones aren't just about reproduction or stress. They're fundamental controllers of metabolism, growth, sleep, mood, immunity, and virtually every other process that keeps you alive and healthy.
At Asele, we believe that understanding your body's biochemistry empowers you to make better health decisions. Whether you're curious about hormone health, metabolic wellness, or personalized healthcare, knowledge is the first step toward optimal wellbeing.
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