What are hormones and how do they work?

Find out about the system that governs your hormone production and learn what hormones are and what they do.

Hormones are chemical messengers that move through the body coordinating bodily processes. Each hormone targets a different part of the body and has a very specific job to do.

What do hormones do?

Hormones are responsible for many body functions, including growth, metabolism, reproduction and homeostasis — maintaining the body’s internal balance. They can also have profound effects on our mood, metabolism and general well-being.

Target cells have receptors that hormones bind to, which triggers a biological reaction that affects the body. A hormone cannot bind to a cell unless it has receptors for it, but cells can have receptors for many different hormones.

What are hormones made from?

There are three types of hormone – protein (or peptide) based, lipid-based and amino acid-based.

  • Protein-based hormones- These include follicle-stimulating hormone (FSH) and the “feel good” hormone, oxytocin.
  • Lipid-based hormones- These are mostly the steroid hormones that are formed from cholesterol with similar structures. They include cortisol, oestradiol, and testosterone.
  • Amino acid-based hormones - These are simple molecules that are not fat-soluble – they include the thyroid hormones, thyroxine and triiodothyronine, and melatonin.


What can hormones tell us about our health?

Although hormonal balance is so important, it is not always our first line of thinking when it comes to investigating health concerns.

Symptoms of hormonal imbalance include:  

With a blood test, you can identify whether your hormones are within the normal ranges and see if they are contributing towards your symptoms.

Hormone disorders are surprisingly common, yet many hormone problems go undiagnosed as it is easy for people to feel that their symptoms are just due to getting older or feeling out of sorts.

Maintaining a healthy diet, with regular exercise, plenty of rest, and lots of emotional happiness is essential for our everyday needs. And in the background, we need our hormones to support us too.

The endocrine glands

The endocrine glands are responsible for releasing hormones into the bloodstream so that they can travel to the target cells and create a biological response.

The endocrine system is a tightly regulated system that manages the release of hormones and their effects on the body. It operates in a signalling feedback loop so that the release of hormones can be increased or slowed down to maintain their effects at just the right level.

There are ten main glands in the endocrine system, the:

  1. Hypothalamus
  2. Pituitary
  3. Adrenals
  4. Thyroid
  5. Ovaries
  6. Testes
  7. Pancreas
  8. Parathyroid
  9. Pineal
  10. Thymus

Each has a very specific role to play in the body - we’ll take a look at each of them and what they do in the following chapters.

Head over to our hormone homepage, or take a look at our hormone test buying guide.



  1. Hopkinsmedicine.org. 2022. Hormones and the Endocrine System. [online] Available at: <https://www.hopkinsmedicine.org/health/conditions-and-diseases/hormones-and-the-endocrine-system> [Accessed 7 July 2022].
  2. Khan Academy. 2022. Types of hormones (video) | Khan Academy. [online] Available at: <https://www.khanacademy.org/science/in-in-class-11-biology-india/x9d1157914247c627:chemical-coordination-and-integration/x9d1157914247c627:human-endocrine-system/v/types-of-hormones> [Accessed 7 July 2022].
  3. Cleveland Clinic. 2022. Hormonal Imbalance: Causes, Symptoms & Treatment. [online] Available at: <https://my.clevelandclinic.org/health/diseases/22673-hormonal-imbalance> [Accessed 7 July 2022].
  4. Hopkinsmedicine.org. 2022. Anatomy of the Endocrine System. [online] Available at: <https://www.hopkinsmedicine.org/health/wellness-and-prevention/anatomy-of-the-endocrine-system> [Accessed 7 July 2022].

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