I Lost My Mom… Then 28,000 People Started Reading My Words

How I found my voice and my readers on Substack in 6 months

photo credit: Sara Redondo with her mom

I’m so excited to introduce you to today’s guest writer,

Sara Redondo, MD

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She’s a real doctor and also one of the most thoughtful and inspiring voices I’ve ever met online.

Sara and I connected through my Substack Bootcamp, then she joined as a founding member, a VIPer. And get this: she grew her newsletter from zero to bestseller and 28,000 subscribers in just six months. Mind-blowing, right?

So many people on Substack can relate and engage with her stories.

After losing her mom, something shifted. That moment stayed with her. It became the heartbeat of her writing.

I’m honored to feature Sara as #6 of the Substack Guest Post Summer series.

And as you’re making her words part of your weekend, I’m sending a warm hello from Venice, Italy.

A city built on millions of wooden stilts, rising from a lagoon, famous for its canals, gondolas, grand old palaces and… Jeff Bezos’ wedding.

We’ve been caught in a heatwave here, so we’ve been hopping from shadow to shadow with the kids, doing our best to stay cool.

One gelato shop shaped our stracciatella ice cream into a perfect rose. Another had a full-on chocolate fountain. And in a funny Spanish gift store, we found GameBoy notebooks and the wildest pens… think Clueless-style, like something Alicia Silverstone (loved her!) would totally carry in her purse.

GIPHY

But now let’s hear what Sara has to say.

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¡Hola! dear Online Writing Club reader,

My name is Sara Redondo, I’m a medical doctor from Spain, and I never thought I’d become a writer.

I went into medicine to help people heal—physically, emotionally, completely. But I quickly realized something painful: the system I was working in didn’t support that kind of healing. It didn’t empower people. It often didn’t even see them as whole human beings.

Over time, I realized that the missing piece was a focus on prevention and whole-person care. I began diving deeper into research on lifestyle medicine, nutrition, stress, sleep, gut health, and the mind-body connection—an exploration that has now spanned over a decade of study, clinical experience, and continued learning. What stood out to me was that much of this knowledge is backed by solid science, but rarely makes it into everyday medical practice.

I witnessed it first as a doctor. Then, most devastatingly, as a daughter. And finally, as a patient myself.

The Moment That Changed Everything

On the last day of my first year of medical school, my mother told me she had been diagnosed with metastatic lung cancer. It didn’t make sense. She had never smoked. She was young, vibrant, healthy.

But the path ahead was shadowed and uncertain.

She was offered chemotherapy, only chemotherapy. There was no mention of psychological support, no guidance on nutrition, no conversation about movement, sleep, or emotional care. Just a treatment protocol and a quiet resignation from the system.

Photo credit: Sara Redondo

Her loss shattered me, both personally and professionally.

Grief pulled me under. I developed depression, anxiety, insomnia, and episodes of binge eating. I felt disconnected from everything and everyone, including myself. And as a future doctor, I knew there had to be more to medicine than this.

My Trust In The System Began To Unravel When My Mom Died

Sometime later, I came across the story of another physician—one with a similar prognosis: advanced, metastatic ovarian cancer. But her approach was radically different.

She combined conventional oncology with an integrative plan: clinical treatment, yes—but also movement, personalized nutrition, emotional care, and complementary therapies. And she survived. In fact, she went on to have children.

I couldn’t stop thinking about it. Why hadn’t my mother been offered this? Why did no one even mention the possibility of integrative care—of supporting her body and mind alongside the treatment? Why was this information, which could have made such a difference, either hidden, dismissed, or simply never brought into the conversation at all?

It was in that moment that my trust in the system began to unravel, and my curiosity finally turned into a mission.

I started diving deep into the science behind integrative medicine, the evidence-based, whole-person approaches that consider the connection between body, mind, lifestyle, and environment. I realized there was a vast amount of research, credible, validated science, that simply wasn’t being used in everyday care.

And that discovery changed the entire course of my life.

I began complementing my traditional medical training with in-depth research into integrative medicine, guided by mentors who shared a more holistic vision of health. I even published my medical thesis on the subject, determined to explore what conventional education so often leaves out.

More than a decade later, here I am, helping people through my writing.

The Words I Was Never Told: My Journey from Doctor to Writer

For years, I carried that pain and disillusionment quietly. I finished medical school, continued working in healthcare, and kept studying integrative medicine, determined to find the missing pieces.

I was helping people—but only within the limits of a system that often felt rushed, reactive, and incomplete. There was no time to explain, no space to educate, and no room to truly connect.

Then, almost unexpectedly, I discovered writing. What began as a way to make sense of my own experience became a way to help others make sense of theirs.

I started writing my first book, and shortly after, launched my first newsletter. Without planning it, I had found a new path, one that allowed me to practice medicine in a different way.

One that allowed me to finally say all the words I was never told, and never got to tell.

Writing the Book I Wish Existed: Delicious Longevity

I began writing my first book, Delicious Longevity, last year, unsure if anyone would ever read it. But the more I wrote, the clearer it became: this was the book I wish someone had handed my mother. The book I wish I’d had when I was struggling.

A practical, science-based guide to holistic wellness through nutrition—designed to cut through misinformation, offer real clarity, and help people build habits that support a vibrant, lasting life.

This book carries everything I’ve learned as a doctor, a daughter, and a patient who refused to accept that healing begins and ends with a prescription.

It’s your invitation to ditch the confusion and reconnect with your health through clarity and confidence. Inside, you’ll find myth-busting insights, answers to most common questions, a comprehensive overview of popular diets—Mediterranean, vegan, vegetarian, anti-inflammatory, ketogenic, DASH, and MIND, and an approachable guidance for everything from gut health and energy to emotional eating and daily habits.

Delicious Longevity provides evidence-based strategies to support mental wellness, increase energy, improve gut health, promote healthy weight loss, balance blood sugar, and enhance longevity and healthy aging—all while helping to prevent the two leading causes of death worldwide: cardiovascular disease and cancer.

You’ll also discover how to enjoy your favorite foods without guilt, while still making meaningful progress toward your health goals. The book offers mindset-shifting techniques to help you create long-term success, so that health becomes a natural, enjoyable part of your life, not a source of stress or perfectionism.

Most importantly, it shows you how to build sustainable eating habits without restrictive diets or sacrificing the joy of eating well.

It will be published soon.

🌟Your Chance! Join My Advance Reader Copy Team

Right now, I’m opening up a few final spots in my Advance Reader Copy Team—a small, trusted circle of engaged readers who’ll receive the book for free before it’s officially released.

If you’re genuinely interested in holistic health and would be willing to support the launch by sharing a thoughtful review once it’s live, I’d be honored to welcome you.

👉If you’d like to be part of the Advance Reader Copy Team, you can fill out your details in this form: https://forms.gle/DYEs9rVprm47xwvX9 👈

Your voice and support could help this message reach the people who need it most.

How a Newsletter Helped Me Share What Medicine Left Out

​​In January 2025, I launched Zenith Within, my Substack newsletter, as a way to keep connecting with people beyond the walls of the consultation room. I needed a space where I could offer the kind of guidance I rarely had time to give during appointments—a space where connection, education, empathy, and evidence could finally coexist.

Zenith Within is where I share holistic, practical, and science-backed health strategies for everyday life. It’s a space designed to help readers cut through the noise with myth-busting guidance, actionable insights, and a compassionate, whole-person approach to well-being.

From Zero To 28,000 Subscribers Within 6 Months

What began as a personal project has since grown into a global community of over 28,000 readers (!) within six months.

People who, like me, believe that true health isn’t just the absence of disease, but the presence of well-being that’s sustainable, grounded, and real.

In June 2025, I already became a bestseller! A dream came true.

Substack gave me the platform to share this vision and the unexpected gift of meeting wonderful people whose support and encouragement helped me grow a vibrant, engaged community.

Kristina God

was one of those people. Her Bootcamp, guidance, encouragement, and generosity played a meaningful role in helping me grow Zenith Within and feel at home in this creator community.🙏

⭐Special Forever Discount To Join Zenith Within

If anyone feels called to join, I’d be truly honored to welcome them. I’ve created a special forever discount for a limited time—it’s my way of saying thank you and making it easier to access everything I share.

Here’s the link to the offer: https://www.zenithwithin.com/foreverdiscount

🙏Thank you, Kristina, for opening your space to my voice.

And thank you, dear reader, for spending this time with me, for reflecting, for connecting, and perhaps even for recognizing a piece of your own story in mine.

With gratitude,
Sara Redondo, MD
Founder of www.zenithwithin.com

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Whenever You Feel Ready, I’ll Be There

Now, before you go, if you’re feeling inspired and ready to start or grow your own Substack, want to find your own voice and be SEEN, here’s how I can support you this summer:

Substack Kickstarter Bootcamp - Write your way to your first $1K

This summer, take the course on demand. Learn Substack at your own pace—from your hammock, your favorite café, or anywhere in between.

It’s usually live, but now it’s fully flexible.

Online Writing Club Membership

Join as an annual member and get full access to the Substack Course for Beginners—already taken by 350+ writers. You’ll also step into our invite-only community and join live masterclasses with top voices in the space.

1:1 Coaching & Personal Feedback

If you’re serious about kicking off or taking your newsletter to the next level, the very best way to work with me is to become a founding member, a VIPer, just like Sara did.

You'll get to meet me live, ask questions in the DMs, and get personal support to help you grow your audience, hone your voice, and get lots of pointers to hit bestseller status.

If you only want to book a 1:1 and work with me directly, you can do it HERE.

Whenever you're ready, I’ll be here to help you write with more heart, clarity, and confidence. Buona notte from Venice!

🖐️If Grief Has Shaped Your Own Writing Journey, We’d Truly Love To Hear About It

• How do you deal with grief in your writing?

• Do you write through it, around it, or because of it?

Feel free to share your thoughts or even a link to something you’ve written in the comments. We’d be honored to read it.

Wait, please, could you do us a favor? 😘Re-stack and/or share this post, so more people can see it!😘 Thanks sooo much!