Hazel Wallace is just home after a celebratory brunch in London, a warm and glittering event to mark the publication of her fourth book, Not Just a Period. She has shared glimpses of the picturesque gathering on her Instagram feed, the pictures nestled alongside her signature posts: beautifully plated blueberry oats recipes for the luteal phase of the menstrual cycle, yoga flows for cramps, and finish-line shots from the London and Paris marathons. Her grid is a blend of evidence-based wellness and digital elegance – but behind the polish is a deeper mission.
The 34-year-old is originally from Blackrock, Co Louth, but now lives in London where she has become one of the UK‘s most prominent voices in women’s health, a medical doctor, registered associate nutritionist, personal trainer and bestselling author. But she wasn’t always on this path. In fact, her early career was shaped not by ambition, but by loss.
“When I was 14, I lost my dad to a stroke,” she says. “It was really shocking. He had a mini-stroke while we were having dinner. He was in hospital for a few days, and then he passed. It was the first time someone in my family had been seriously unwell, and it changed everything.”
The grief, she says, didn’t arrive all at once. “I didn’t fully understand it at the time. I missed a lot of school. I became socially withdrawn. I didn’t take care of myself.”
In the aftermath, her interest in medicine grew – slowly at first. “His death was partly preventable, and I think that stuck with me. I became really focused on health in a broader sense – nutrition, stress, movement – things we hardly touched on in medical school.”
Wallace didn’t get the points she needed to study medicine in Ireland, but she was determined to pursue her passion so she headed to Wales to do medical sciences, followed by medicine at Cardiff Medical School. In 2012, as a first-year med student, she started a blog called The Food Medic.
“Honestly, I started it for myself,” she says. “I wanted to learn more about nutrition, about how lifestyle affects health. It was a way of figuring it out in public.”
The blog and her Instagram following rapidly grew as she moved to London in 2016. Her ascent coincided with the rising popularity of wellness influencers, some of whom spread dangerous misinformation. Wallace‘s platform stood out because it was grounded in science. “There was this moment when people started demanding more credible advice,” she says. “And I was one of the first few with both a medical and nutrition background.”
The blog blossomed into several books, media appearances and, now, an online community of more than 1.1 million followers. But that success came at a cost.
“For a long time, I had an unhealthy relationship with productivity,” she admits. “I tied my self-worth to academic success and professional output. I think I was also using it as a distraction – if I was busy, I didn’t have to stop and feel.”
The pandemic, she says, made the limits of that model painfully clear. “By the second year of Covid, I was working in one of the only long-Covid clinics in the [UK]. There were just four of us. On weekends, I was covering intensive care shifts. I was exhausted and completely burnt out.”
She took a step back from work, intending it to be temporary. “But I didn’t go back. It was hard to let go of that identity – I always thought of myself as a doctor in scrubs. But I wasn’t well. And I knew I couldn’t keep going like that.”
This shift had come after a health crisis had already given Wallace a reason to slow down. In 2016, she began experiencing symptoms that didn’t quite add up. After two years of pushing for tests and consultations, she was finally diagnosed with PCOS – polycystic ovary syndrome, a hormone condition affecting one in 10 women which can lead to irregular or absent periods, difficulty conceiving, acne, anxiety, weight gain and excess hair.
“I was already a qualified doctor, and it still took years and a lot of self-advocacy to get a diagnosis,” she says. “Even then, the advice was basically, ‘Come back when you want to get pregnant.’ That was it.” The experience left her feeling adrift. “I still felt in the dark about what to do. And if I felt that way with a medical background, how must everyone else be feeling?”
This experience was part of what drove her to write her third book, The Female Factor, which explored how the male body has always been the default body in clinical medicine and research, leaving so much of women’s health unexplored, unacknowledged and unsupported. The Female Factor aimed to be a comprehensive guide to women’s health and included facts and tips on hormones, nutrition, mood, sleep and recipes.
Her PCOS diagnosis had also prompted Wallace to think about fertility. She wanted children, but didn’t feel ready for them yet, and decided in 2023 to freeze her eggs – an experience she eventually shared with her followers. “I documented the process but waited until I was through it to decide whether or not to post. Even with all my training, it was intense – emotionally and physically. The daily injections, the hormone swings. It caught me off guard.”
What struck her most was how little practical information there was. “It made me realise just how many gaps exist – not just in care, but in what women know about their own bodies. That’s what compelled me to share my experience. I knew if I was surprised by the process, others would be too.”
During the pandemic, Wallace had noticed a disturbing trend whereby some women were attributing a disruption in their menstrual cycle – most likely caused by the stress of the pandemic – to the Covid vaccine, reinforcing anti-vax conspiracy theories. Without basic information about how periods can be affected by stress, misinformation and fearmongering grew. “People were convinced the vaccine was disrupting their periods, but the research showed it was temporary and likely stress-related,” she explains. “It really highlighted how little we understand about menstruation – even among people who menstruate.”
We‘re taught to ignore hunger, to keep ourselves small. But your metabolic rate increases before your period - that’s why you’re hungrier. That’s not weakness. That’s biology
— Dr Hazel Wallace
That gap in understanding was one of the catalysts for Not Just a Period, which aims to be a comprehensive, empowering guide to the menstrual cycle. She‘s particularly critical of the way women’s pain and mood are pathologised. The book highlights that women are statistically twice as likely to experience depression, especially around hormonal shifts like puberty, the premenstrual phase, post-partum and menopause – but instead of receiving support, women are dismissed, patronised and laughed at. “Instead of support, we‘re often dismissed. We‘re told we‘re being ‘moody’ or ‘emotional‘. But those mood changes often have physiological roots – and they deserve proper care.”
She points to PMDD – premenstrual dysphoric disorder – as a prime example. “People with PMDD can lose years of their life to disability. But they’re frequently misdiagnosed or not taken seriously. It’s not just frustrating – it’s harmful.” In the book Wallace highlights the medical gaslighting that women often experience, and the shame that prevents women from taking paid sick leave off for periods of PMDD, instead suffering in silence and losing money to a health issue that should be treated as such.
Wallace‘s book doesn’t shy away from these hard truths. But it also offers practical tools – how to work with your cycle instead of against it, how to recognise shifts in mood or energy, how to support your body nutritionally through each phase. She also encourages cycle tracking, which she sees as a vital tool for body literacy. “It’s not just for fertility,” she says. “It’s about understanding yourself. Noticing patterns. Feeling more in control.”
Still, she recognises the complexities around menstrual data and privacy. When I ask about how some American women have stopped using tracking apps due to political changes in reproductive rights, she‘s sympathetic. “I completely understand that concern. In the UK, we’re not facing the same kind of threats, but it’s a reminder that we need to be informed about where our data goes. Transparency matters.”
[ What is causing girls to get their period at an earlier age?Opens in new window ]
Another key theme in the book is how diet culture intersects with menstruation, noting that many women see an increase in appetite around their period but don’t feel able to fuel themselves because we‘ve been taught to value thinness over our bodies’ needs. “We‘re taught to ignore hunger, to keep ourselves small. But your metabolic rate increases before your period – that’s why you’re hungrier. That’s not weakness. That’s biology.”
Wallace sees the consequences of this first hand in her practice. “Women restrict, then binge. Then feel guilty. It’s a cycle that can be avoided if we just listened to our bodies more and judged them less.” Body image also takes a hit premenstrually, she notes. “Even if nothing physically changes, many women feel bigger, bloated, uncomfortable. The way we speak to ourselves becomes harsher. Understanding that it’s hormonal can really help shift the narrative.”
Social media complicates the issue of body image further. Wallace recognises the tension between trying to educate women about body image, health difficulties and natural struggles on a platform known for perpetuating rigid beauty standards and toxic comparisons.
Wallace’s own social media matches a lot of the aesthetic standards that can make health education feel alienating to some: she is slim and attractive, her recipes are colourful and prettily presented, and even while training for marathons she manages to look pulled together while jogging and balancing a camera to capture her journey. She‘s aware of the danger of “the highlight reel” vision of life that Instagram can create, and is wary of pages that promote a certain body type rather than education about health and lifestyle choices.
“Instagram has been incredible for sharing information, but it also promotes a narrow beauty standard. Even when posts are well intentioned, they often still centre bodies that meet narrow beauty standards,” she says. “I try hard not to put my body at the centre of my content. It’s about the message, not the mirror. It’s not about how I look. But a lot of health influencers still lead with abs, with before-and-after shots. It’s toxic – and it’s confusing. People assume that if they follow the advice, they’ll look like the person giving it. That’s not health – that’s marketing.”
Still, she admits the pressure to create content that reaches audiences can be exhausting. “There‘s this constant push to make content prettier, punchier, faster,” she says. “And educational content – especially about periods – is not favoured by the algorithm. You have to work extra hard to be seen.”
Wallace’s marathon training videos and recipes for the luteal phase might look effortless, but she schedules shoots like shifts. “It’s my job,” she says. “But I’ve also had to protect myself.” She‘s developed rules: no scrolling before 8am or after 6pm. “Even I get caught in the comparison trap. I’d look at other creators and think, ‘I should be doing more.’ And that’s not sustainable.”
As she looks ahead, Wallace is preparing for her wedding this autumn in Greece to online fitness coach and Too Hot To Handle star David Birtwistle. But for now, she‘s trying to slow down and give this book the space it deserves.
“I’ve been guilty of rushing into the next thing. Not this time. I want Not Just a Period to land, to start conversations, to help people. Menstrual health affects everything – our ability to work, our relationships, our mental health. And yet it’s still whispered about,” she says. “I want Not Just a Period to change that.”
Because to Wallace, the menstrual cycle isn’t just a health issue. It’s a lens through which we understand how the world treats women – and how women are taught to treat themselves.
Not Just a Period is published by Bluebird, an imprint of Pan Macmillan.
