For any women approaching her thirties, hormonal health is a big topic. Whether you want to have children in the future, have concerns about your reproductive health or you’re simply intrigued about your hormones, it’s natural to want answers about your body.

Yet this area is woefully under-researched. A 2014 report found that less than 2.5% of publicly funded research is dedicated solely to reproductive health, despite the fact that one in three women in the UK will suffer from a reproductive or gynaecological health problem and one in six couples struggle to conceive. Plus, how many times have we been told that our fertility 'falls off a cliff' by age 35?

It's little surprise, then, that the market for at-home hormone tests is booming. These finger-prick tests work by measuring the amount of hormones in your blood, which can offer insight into fertility, egg reserves, hormone imbalances and menopausal symptoms. In the past few months, I’ve noticed adverts popping up on my Instagram feed for services promising a detailed analysis of my hormones in as little as ten days. They are also easily available on the high-street and more affordable than a test with a specialist, with prices ranging from £39.99 to £149 depending on the test you choose.

However, a new report published this week in The British Medical Journal (BMJ) has warned that some DIY tests sold in the UK that measure oestrogen levels might give misleading results. This is because levels of oestrogen in the capillaries, the tiny blood vessels in your fingertips, tend to be significantly lower than levels in the vein. The report in the BMJ said that the Eurofins laboratory was still processing finger-prick tests for oestrogen levels on behalf of private firms who sold them online, even though other testing labs had changed the way they processed oestrogen tests.

Are at-home fertility tests reliable?

It isn't known which companies use the Eurofins lab to test their samples, but experts acknowledge there are difficulties with measuring certain hormones, which could be amplified by at-home tests. Richard Anderson, Co-Director of The Centre For Reproductive Health at The University of Edinburgh, explains that oestrogen is a tricky hormone to measure because there’s a very low concentration. ‘This is a general problem for blood measurements of oestrogen when it’s at low levels, under all circumstances. If you’re doing it in a tiny drop of blood from a finger press, then that’s going to amplify the difficulties of doing the assay,’ he told Grazia.

Alongside oestrogen, companies offer testing for a wide range of hormones, including the anti-Müllerian hormone (AMH), which can help estimate the number of follicles inside the ovaries, and progesterone, which is used as a marker of ovulation when investigating infertility.

However, Professor Anderson points out that ‘AMH is not useful in predicting which women will and will not get pregnant in the next six months or a year’ adding ‘it’s useful in predicting how well a woman might do in an IVF cycle, so to have it as part of a fertility test is a complex question.’

That’s not to say these tests aren’t accurate, but we do need to be clear what questions we are asking from them. Lauren Johnson Reynolds, 34, aka The Wellness Coach, was diagnosed with ‘borderline’ Polycystic Ovary Syndrome (PCOS) when she was 14 and told she wouldn’t be able to get pregnant. She was prescribed the contraceptive pill to manage her symptoms when she was 17, and when she was 30, she decided to take an at-home hormone test. ‘I hadn’t had a real diagnosis since I was 14, and I wanted to know where I was at with my hormones,’ she says.

The results of Lauren’s test all came back within the ‘normal’ range. ‘Looking at them now, with the knowledge I have about hormones, I can see that my results do indicate PCOS, specifically that my LH and FSH levels were in a ratio that normally indicates [the condition],' she says.

However, the test did lead to Lauren getting a proper PCOS diagnosis. 'Although my results were normal, because I had irregular periods, which is one of the questions that comes with the test, they recommended I should go to my doctor and get a scan. So it was thorough in that respect,' says Lauren. She adds that since she took her test four years ago, one company has updated their reference range to include ‘optimal', rather than just 'normal.'

Lauren, who is now a mother, thinks that the tests are still ‘a great way to take matters into your own hands.’ She uses at-home fertility tests with her own clients, but always works with them to interpret the results. ‘The best way you can use these tests is to work with a practitioner’ she says. ‘The average person is going to be depending on what the company says about their results. You can get a result and think “oh my god my AMH level is low”, that means I’m going to have to freeze my eggs. But people with a low AMH get pregnant all the time, so you’re not getting a full picture of your health.’

It's easy to see the appeal of these tests. In the UK, you usually need to have been trying for a baby for at least a year before your GP offers you hormone tests related to fertility. Meanwhile, waiting times for gynaecological appointments in England have trebled in the last decade, with women now waiting an average of four months for a first hospital appointment. But, as with many at-home tests, there's room for misinterpretation when it comes to the results.

‘I think it is very good that patient friendly technology is being developed to facilitate testing. However, it’s important that these tests are properly validated for accuracy and consistency and that the results are interpreted by medical professionals who are familiar with the patients’ medical history,’ says Marta Jansa Perez, director of embryology at The Bridge Clinic. ‘Fertility patients are keen to understand their own fertility and the reasons for failing to conceive but self-interpretation of test results that have not been validated could lead to misinformed decisions when it comes to fertility interventions and treatments.’

Plus, receiving worrying results at home, without the presence of a medical professional, could take its toll on our mental health. ‘They can be useful, but they can also generate a lot of stress, anxiety and unhelpful knowledge,’ adds Professor Anderson. Many companies which sell at-home tests do offer 1-1 counselling services, although it’s up to the customer whether they take these on.

Ultimately, these tests can be an empowering and affordable way for women to gain a greater understanding of their bodies in an area where science has all too often let us down. But it's important we take them for what they are; a helpful insight into the complicated wider picture of our reproductive health. If you are planning on taking one, make sure to follow up any concerns you have with your GP.