The Biology (& Chemistry) of Happiness

I want to discuss the science around happy hormones with you. We often talk about science like it’s one person saying that things are and aren’t correct, but really, there are lots of scientists and sometimes they don’t all agree.

The biology and chemistry of happiness - happy hormones

All of science is theory. There are some theories we’re pretty sure about and some that are still being proved. We always recommend doing your research and not following any random humans on the internet when it comes to your health and wellbeing. 

With all that said, let’s get on with some fun science!

Chemistry, My Dear Watson 

Brains are notoriously difficult to understand. There’s a reason we use the phrase “it’s not brain surgery”. A lot is going on in the human mind, and we do not understand all of it… not even close!

When it comes to happiness in people there are a few things we do know. The chemicals that help us regulate our mood and make us happier have been studied in a lot of depth. We’re going to look at four key chemicals. When you find them in the brain, they’re called neurotransmitters, but if you find them in the rest of the body they’re called hormones. 

They function slightly differently in the brain than they do in the rest of the body. For example, Serotonin in the body helps regulate your digestive tract, and in the brain, it helps regulate your mood. To help keep these functions separate we’ve developed something called the blood-brain barrier. This is a very useful function because it means that when we use the toilet facilities (couldn’t bring myself to write this more graphically), we don’t experience a rush of joy simultaneously. Whilst that sounds like we would want that, we can’t have people experiencing euphoria every time they visit the toilet – it would be too much!

Serotonin is only one of the neurotransmitters we’re going to look at in this post. The others are Dopamine, Oxytocin, and Endorphins. Probably, you will have heard of all these hormones, and how they impact your happiness – but hopefully, you’ll learn something new here anyway. 


What Does It Do?

Dopamine is used for a tonne of different things in the body and the brain. It plays a part in the kinds of things that make us human, like learning, lactation, perseverance, pain reception, sleep and even movement. Of course, it’s also got a big part to play in our mood. 

Dopamine is sometimes called the “pleasure hormone”. This is because when we produce it we feel enjoyment and reward. Our bodies are designed to produce dopamine when we’re doing things our body wants us to continue doing. This includes when we’re eating delicious foods when we’re achieving our goals, and when we’re having sex. Interestingly we also get a dopamine hit when we get likes/retweets/shares on social media… part of the reason it’s so addictive! 

How Do We Make It?

Dopamine is a great little chemical. It’s the smallest chemical we’re going to discuss today, structurally. However, don’t let its size fool you – this guy packs a punch!

Our bodies synthesize dopamine from amino acids. This is why it’s really important to make sure you get enough protein in your diet. If you’re cutting down on your meat consumption, there are alternatives like eggs or soy products. These are great because they’re what are called “complete proteins” which means they contain all the amino acids your body needs. However, an alternative is to eat a wide range of protein sources. 

Recent studies have shown that excessive consumption of saturated fats may disrupt dopamine production, so this might be something worth looking out for.



Serotonin only gets widely discussed in the context of SSRIs which are a family of drugs that help treat depression and anxiety. Chronic serotonin deficiency can result in anxiety and depression, and even sleeplessness. SSRIs help prevent the reabsorption of serotonin, meaning there’s more to go around. 

What Does It Do?

As we alluded to previously, serotonin mostly hangs out in the gut, but it also has some pretty important functions in the brain as well including regulating eating and sleeping. Not having enough serotonin leads not only to anxiety and depression, as we discussed, but has also been linked to gastric symptoms.

Serotonin is important in regulating your brain. When your serotonin levels are normal, you’ll feel calmer, more focused, less anxious and generally happier. 

How Do We Make It?

Our bodies make serotonin using tryptophan. This is an amino acid, and you can actually get supplements for it, but it’s usually best to get it from your diet. You probably eat plenty of tryptophan-rich foods already, they include eggs, salmon, tofu, turkey and even pineapple. 

Studies have shown that eating carbs alongside tryptophan-rich foods can help give a serotonin boost. Another reason to heap on the roasties with your Christmas turkey dinner, and a scientific explanation for the feelings of joy as you sink into the sofa afterwards. 


Sometimes known as the “love hormone” oxytocin has something of a reputation because it tends to be associated with reproduction. But there’s much much more to this one. 

What Does It Do?

Oxytocin is linked to trust and relaxation but also plays a key part in lots of other processes. Interestingly production of oxytocin in the brain also boosts the production of dopamine and serotonin, which as you already know will help you feel happier.  

In the body, oxytocin is used in a bunch of family-related processes including lactation and labour. However, it is also used in the brains of both men and women to induce bonding with their kids. Studies show that men exploring with their kids can supercharge this, but in both genders bathing, singing to and getting skin to skin contact with babies will help produce oxytocin. The baby doesn’t even need to be yours, so you can boost your levels by babysitting. 

How Do We Make It?

As with the other neurotransmitters, our bodies create oxytocin from amino acids. If you’re eating a generally healthy balanced diet, you should have everything you need for your body to make it. Some studies suggest that topping up vitamin C levels will support production. Your body also needs magnesium to produce the receptors which help you to process oxytocin. 


These guys are the best known of the happy hormones, or chemicals. Most of us will be familiar with the post-exercise endorphin rush. 


What Do They Do?

Scientists aren’t sure about all the functions that endorphins play in our biology. Some of the things they have definitely been linked to include socialisation, weight control, and even dealing with the pain of childbirth. 

Endorphins, like dopamine, are also linked to our reward response, to help us keep doing things our body wants us to do. Hence, the link between exercise, endorphins and happiness. Similarly connecting and socialising with others releases endorphins, which is evolutionarily key to our survival as a species. 

How Do We Make Them?

Endorphins are made from amino-acid chains, so here, yet again lots of protein is key. Make sure you get it from a wide range of sources. However, food has another role to play here – some foods can stimulate the production of endorphins, like dark chocolate, red wine, and even the humble banana. 

How To Increase Happy Hormones In Your Team

Here’s the fun part, a lot of these chemicals are made through the same kinds of activities. Yoga for example will help you create endorphins and serotonin; hugging your pals will help you produce oxytocin and endorphins; eating a healthy, balanced diet will help you produce all four! This is a small part of the reason lockdown has been so hard for us. We need (and miss) human interaction to increase happy hormones.

In the work context there are lots of things you can be doing to help make sure your people are creating all the happy hormones they need. As you can see from the above, physical and mental health are intrinsically linked, so making sure your team has plenty of time to eat healthily, move their bodies, and get enough sleep is key. Beyond this each human being is different and unique, so our main tip here is to make sure you’re listening to your people.


Although they might not understand the exact science behind why they want more fruit, outdoor meetings or flexible work schedules – they intuitively know what they need to increase their happy hormones. 

This is inspired by chapter 8 of my book, Freedom To Be Happy: The Business Case for Happiness.

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