Back to basics: What do hormones do in the body?

So we’re pretty obsessed with our hormones. Okay, that’s an understatement—we’re undeniably, categorically, unapologetically, o b s e s s e d with our hormones. 

Why? Because they’re one of, if not THE most, amazing biological functions of the body. Those tiny little molecules are zooming around our bloodstreams day and night, never slacking, always fighting hard to keep us fit, functioning and fierce honey.  

Hormones are involved in almost all of our body’s processes, from helping us put one foot in front of the other to getting our 8 hours of shut-eye a night. We totally take them for granted (literally every living second) and most of us just don’t know half of what our hormones get up to behind the scenes. 

So let us introduce you to your wonderful, magical, o’so fabulous hormones…

What exactly are hormones? 

Hormones are teeny tiny molecules that act as the body's chemical messengers (think WhatsApp for the bloodstream). Essentially they carry messages from one part of the body to another, telling various body parts what’s what and who’s who.  

Hormones are transported in the blood and travel all over the body, but they can only affect the specific cells designed to work with them. 

This is often referred to as a ‘lock and key’ mechanism, where each hormone has a specially shaped receptor (like a key) that fits with certain specially paired receptor sites (like a lock) (1) If you’re wondering, ‘what do hormones look like?’, well this diagram is our personal take on it. 

After the hormone pairs to its chosen receptor, in the cell membrane or nucleus, they release a set of instructions to the cell. From there, the cell gets to action, bringing about allll the changes it was instructed to (cells are very hard workers), initiating a cascade of changes throughout the whole body.

What do hormones regulate? 

Hormones are made in glands (organs) all over the body, and these glands all collectively makeup what’s known as the endocrine system and then each hormone regulates a specific bodily process. Let’s take a closer look at the 9 major glands and what their hormones regulate:

1. The hypothalamus (‘the controller’): the hypothalamus has got our backs, keeping eveeerything in balance. It regulates our body temperature, hunger and thirst, emotions, blood pressure, sleep and sex drive (2).
   
   

2. The pituitary gland (‘the top dog’): the pituitary is a small but o’so mighty gland, controlling many other glands in the body. It’s where most hormones are made before they are dispersed in the blood to do their jobs at other glands (3).
   
   

3. The thyroid (‘the personal trainer’): The thyroid plays an important role in regulating metabolism, heart rate, muscle growth and digestion, allll the things trying to keep you lean and healthy (4).
   
   

4. The parathyroids (‘the bone mass master’): The parathyroids regulate everything to do with calcium, controlling how it’s released from bones, absorbed from food and conserved in the kidneys (5).
   
   

5. The adrenal glands (‘the stressy ones’): The adrenal glands produce stress hormones, like cortisol and adrenaline, which help regulate a whole load of bodily functions and responses, from our ‘fight or flight’ response to our immune system (6). 
   
   

6. The pineal gland (‘the body clock’): the pineal gland controls our sleep-wake cycle by producing the hormone melatonin, telling us when it’s time for some shut-eye (7).
   
   

7. The pancreas (‘the foody’): the pancreas makes digestive enzymes and shoots them into the small intestine to help digestion and ensure we absorb all the good bits. It also helps control blood sugar levels (8). 
   
   

8. The ovaries (‘the menstrual matriarchs): the ovaries are everything to do with female sexual development, secreting female sex hormones like estrogen and progesterone which control the menstrual cycle.
   
   

9. The testes (‘the sperm banks’): the testes are everything to do with male sexual development, secreting testosterone and producing millions of sperm.

Why are hormones important for our health?

As we’ve seen, it's near impossible to talk about any major body part, process or function without mentioning our wonderful, multitasking hormones—without them we’d literally be unable to function. 

Keeping ourselves healthy means keeping our hormones healthy too. With all of their rushing around, our hormones are sensitive souls and can easily get knocked off balance. Hormone imbalances are suuuper common and can be caused simply by lifestyle factors or from more serious endocrine disorders (like diabetes or Polycystic ovary syndrome (9)). 

What’s more, everyone's hormones are different. Just like our fingerprints, our hormonal profiles are totally unique.

Some of us are also more sensitive to certain hormones. Take progesterone for example—people more sensitive to progesterone's calming qualities are more likely to suffer from low moods or PMS-type symptoms just before their bleeds (11). Whilst others may not notice any mental menstrual shifts.

Want to learn more about your fabulously unique hormones?

Getting to grips with our hormones can have huge benefits—for our health, informing our lifestyle choices and things like what kinds of birth control could work well for us. 

If you think you might have a hormone imbalance, are looking for the right birth control for you, or if you just want to learn more about your body, we can help you do allll of those things (and then some). 

Understanding our hormones also means gaining an understanding of how our bodies are working and appreciating the magnitude of what these little molecules get up to.

Written by

Annalisa Hayes (she/her)

Copywriter at Tuune, Annalisa has worked for various pioneering health-tech startups and healthcare companies with purpose-led missions. Driven by empowering people to take control of their health, she helps make the science behind hormones accessible for our community, so they can make clued-up choices about their healthcare.

Medically reviewed by

Dr. Alejandra Elder Ontiveros, MD, PHD (she/her)

Ale is a PhysicianScientist with a doctoral degree in Development Biology and Embryology and is currently a Postdoctoral Scholar at UCSF. Ale believes that the union of academia and business can lead to transformative discoveries for women’s health.

Scientifically researched by

Hannah Durrant (she/her)

Hannah is a Biomedical Content Writer at Tuune, with a BSc in Biomedical Sciences from University College London. She is passionate about bringing together the scientific community and the general public by disseminating modern science via digestible, engaging and thought-provoking content.