Sarah Horgan

Toxicologist & PhD Candidate, Edinburgh Napier University



Embrace opportunities, find what you love and learn to excel at it.


Being a toxicologist means that I identify and evaluate the potential adverse effects of various different chemicals and substances, some of which you might come across daily (for example cosmetics, cleaning products and food additives). This helps to keep people safe.

In short- my PhD research focuses on checking whether certain bio-nanomaterials (up to about 100,000 times smaller than the diameter of a human hair) are toxic to the reproductive system and whether they disrupt the bodies hormonal system or not.


I’ve had many experiences which encouraged me to choose science as a broad discipline- for example, I recall building electrical circuits in school, my mom giving me a children’s microscope for Christmas one year and doing titrations in secondary school. A few special teachers also played a part in my choice- my chemistry teacher was one of the best teachers I’ve ever had and the first woman in science I learned from. I also had a brilliant biology teacher who had previously worked in a lab and I remember being so inspired by her. In my very first year of secondary school, a teacher told me I was a scientist because of how I approached problems. He was the first person to tell me to pursue science and made me feel like I could really go for it.

Two key moments that inspired me to choose toxicology as my focus. Firstly, when I was in primary school, a charity visited our class to speak about the damage to human health caused by nuclear power accidents around the world. That triggered an interest in me to understand how people were affected by these disasters (even years after they happened) and how best to help those affected. Secondly, when in my third year of my biochemistry undergraduate degree, I chose pharmacology and toxicology as optional modules. While I loved science, I felt lost about what direction I would go in after graduation- until I walked in to my first toxicology lecture and was completely spellbound- I knew I had found my “thing”.


To start, I wish I knew as a child that women are very successful in science. I unfortunately didn’t hear about, or see, many women in STEM for a long time growing up. Because they weren’t visible to me at the time, I didn’t fully realise that a career in science could really be for me.

I wish I knew that it is possible to get a traineeship at a European Agency or any other organisation you are passionate about- I did a traineeship at the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) in Portugal after years of putting off applying.

I also wish younger me knew that getting both a BSc and MSc degree is possible if you are the first generation in your family to go to university. I wish I knew that academia isn’t the only career path that can be rewarding and fulfilling. Some of the best and most creative scientists I’ve worked with either don’t have a degree, or have a BSc and aren't working in academia. If you’re interested in doing a PhD but for whatever reason you can’t/don’t want to do it straight after your BSc/MSc degree, that doesn’t make you any less capable. In fact, I’ve found that working in between can really help you gain confidence, skills and contacts, while increasing your career prospects afterwards.


I love working in STEM because it’s so applicable to everyday life in some way. I love knowing that I've contributed a little to a body of scientific knowledge that may one day help someone, or help us understand a process that we don't yet fully have a grasp of.

I also love working with other scientists- seeing how people approach problems in different ways and collaborating with others to solve a problem is such a great feeling and I learn so much from others- even scientists in different fields.

One of the best things about working in STEM is the variety- every single day is different.


Embrace opportunities, find what you love and learn to excel at it.

Join the science community on Twitter - I’ve made some friends and I saw both the traineeship and my PhD advertisement on there!

Don’t compare yourself to others and get comfortable with rejection. I went to a talk last year where someone who has had an amazing career went through their career timeline, including all the rejections, things that went wrong and jobs that just weren’t for them. Careers in STEM can look easy on paper but remember that we are all only human and for every success, there has been a lot of failures too.

As a woman in STEM, you will face inequality. Know that you are not only working towards equality for yourself in STEM, but also for black, Asian and minority ethnic groups, trans woman, non-binary people and women who are part of the LGBTQ+ community too.


"Courage is like - it’s a habitus, a habit, a virtue: you get it by courageous acts. It’s like you learn to swim by swimming. You learn courage by couraging." - Marie Daly