Welcome to The Weekly Dose, you beautiful bags of microbes… this week we’re going to be diving into a new study looking at creatine in peri/menopause, how to easily eat more fermented foods and one of the most important life lessons I learned…Enjoy!

Creatine for the Menopause Brain? 

Creatine has long been associated with the gym…athletes, muscle mass, lifting heavier. 

But a new randomized controlled trial looked at something totally different: creatine supplementation in peri- and postmenopausal women, specifically its effects on the brain, mood, and metabolism.

This is not a population that creatine research usually focuses on.

Most studies have historically been done in men…young men, athletic men, military men. Women’s physiology, hormone environments, and metabolism during midlife are extremely different; yet they’ve been chronically under-studied.

So this trial matters, even if it’s small.

The research

Researchers followed 46 women, aged 40–60, over 8 weeks.

These women were either peri- or postmenopausal; meaning they were in the stage where estrogen fluctuations are affecting:

• Mood

• Cognitive sharpness

• Energy production

• Sleep quality

• Muscle and metabolic resilience

They tested creatine hydrochloride in different daily doses (750–1,500 mg/day), and a variant formulation.

They used creatine hydrochloride as it is:

• More soluble

• Easier to mix

• Often gentler on digestion

• Effective at smaller doses than the standard 5g/day monohydrate used in sports research

Results

• Reaction time improved by ~12%

• Brain creatine levels in the frontal lobe increased by ~16% (the region involved in planning, focus, emotional regulation)

• Improvements were seen in lipid metabolism (which tends to change during menopause)

• No adverse effects were reported

Women also reported improvements in:

• Cognitive clarity

• Mood stability

• Fatigue and emotional fluctuation symptoms

This aligns with what we already know about creatine; it supports cellular energy production…not just in muscles, but in the brain.

And during menopause, the brain is working harder to maintain energy balance as estrogen declines and so creatine may act as a buffer.

Nuance, nuance, nuance!

We have to appreciate some limitations of this research as it was:

• A small study (n=46, with some drop-outs)

• Short duration (8 weeks)

• Not powered to answer every question about dose, timing, or who benefits most

So whilst this study isn’t definitive or a prescription, it is a starting point.

Future studies need:

• Larger sample sizes

• Longer follow-up

• Comparison with creatine monohydrate

• Hormone-stage-specific analysis

Practical takeaways

Based on not just this study but the cumulative knowledge from previous data we can pretty confidently say that creatine is:

• Safe for most people

• Well-studied

• Inexpensive

• Already known to support muscle, cognition, and cellular energy

And this study suggests it may be especially relevant in midlife, when energy production and brain resilience are under strain.

If someone wants to try creatine and is peri- or postmenopausal, a small daily dose of creatine monohydrate (3–5 g/day) is still the most evidence-based place to start…until more direct women-specific research emerges.

As always…individual health context matters. Speak to your doctor if you have kidney disease or other metabolic considerations

Secret Fermented Foods You’re Already Eating!

When people hear “fermented foods,” they usually picture something bubbling away on a countertop: kimchi, sauerkraut, jars popping and fizzing. But fermentation is not a niche health trend…it’s something woven into everyday eating.

It’s ancient…ordinary…and everywhere!

Some of the most familiar foods in your kitchen rely on fermentation somewhere in their production process:

• Soy sauce

• Worcestershire sauce

• Tabasco and other hot sauces

• Miso

• Tempeh

• Apple cider vinegar

• Coffee

• Tea

• Non-alcoholic beer

• Marmite / Vegemite

Fermentation has been one of humanity’s oldest tricks: transforming basic ingredients into foods that store longer, taste richer, and carry compounds our bodies wouldn’t otherwise have access to.

Fermented foods aren’t the same as probiotics

This is where the confusion begins. Probiotics are specific strains of bacteria that, in the right person and under the right conditions, can have benefits. But they only “count” as probiotics if they’re alive and reach the gut in sufficient numbers. And not everyone responds to probiotic supplements the same way.

Fermented foods, however, don’t rely on whether microbes are alive at the point of eating. During fermentation, microbes produce an entire ecosystem of beneficial compounds…organic acids, peptides, vitamins, short-chain fatty acids, even structural fragments of their own cell walls…that can interact with our immune system and gut lining, whether the microbes are still alive or not.

These are what scientists call postbiotics and even “dead” microbes still have effects.

They can help strengthen the gut barrier, influence immune signaling and help maintain balance in the gut ecosystem.

This is why nearly everyone benefits from including fermented foods daily, even if they don’t tolerate or respond to probiotic supplements.

Fermented foods are broad, safe, gentle, and adaptable to nearly any diet.

Non-pretentious ways to add ferments daily

Keep it simple. Fermented foods don’t need to be fancy or fermented at home like you’re starring in a Netflix homestead documentary.

Just try:

• Stirring miso or soy sauce into soups, broths, or marinades

• Using apple cider vinegar in salad dressings

• Adding a spoon of kimchi, sauerkraut, or pickles on the side of lunch

• Choosing sourdough bread over standard white bread

• Swapping in kefir or natural yogurt a few times a week

1–2 small servings per day is enough to make a measurable contribution to gut resilience.

PS: Fermented foods work best on a microbiome that’s fed. Ferments bring beneficial signals but you also need to lay the foundation for your gut microbes. Your microbiome runs on prebiotic fiber…and different microbes need different fiber types. That’s why diversity matters.

This is exactly why we’re launching LOAM; a clinically-designed multi-fiber prebiotic blend engineered to nourish a broader range of beneficial gut bacteria, supporting not just microbial diversity, but resilience.

Think about ferments as the spark and fiber as the fuel.

LOAM is available from Wednesday 6am PST/1pm GMT, so set your alarms or make sure you sign up on the waitlist to get an email reminder and priority access as well as some exclusive freebies:

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Things I Wish I Knew Before My 30s…

There’s a phrase people love to repeat when you try something new: “Stay in your lane.”

As if the lane you were born into, or studied in, or happened to fall into at 22, is the lane you must drive for the rest of your life. 

But look at the world we live in.

• Lamborghini started as a tractor company.

• Samsung began as a grocery trading business.

• LG sold facial creams.

• IKEA sold pens.

Their stories didn’t end where they started…they evolved because someone, somewhere inside those companies, refused to believe that the first version of themselves was the final one.

The same is true for us.

Your identity is a process

Neuroscience has a word for this: neuroplasticity…the brain’s ability to change through experience. Your brain is not a fixed structure, it rewires based on what you do, what you try, what you learn.

Every new skill, conversation, challenge, or environment lays down new neural pathways and so your identity is not something you discover rather something you build.

So…that means it can change.

The danger of “staying in your lane”

Psychology has shown that when people are told to “stay in their lane”...whether explicitly or subtly…they are more likely to:

• Play small

• Avoid risk

• Suppress curiosity

• Prioritise approval over authenticity

Basically it leads to a form of psychological stagnation where the world is moving, but you’re cycling in place.

Never forget that curiosity is the oldest form of intuition. Our ancestors literally survived because we wandered, we experimented, we explored. You are not meant to be one thing.

I’m in a new era of my life

Marriage. Starting a business (building something with no business degree, no handbook, no roadmap…just the willingness to learn in public)

I have plenty of fear in that, of course but also a strange peace because I’ve come to realise that staying in your lane just delays the moment you confront who you could have been.

My real failure isn’t making mistakes but shrinking myself to fit a life that no longer fits me.

Growth requires permission (your own)

Imagine this; if a plant outgrows the pot…do you blame the plant?!

No…you re-pot it so it can expand.

But for some reason, when you outgrow your own biological pot, we tell each other to stay small.

No one is coming to announce the next version of your life…you have to declare it yourself.

Don’t stay in your lane…but stay in your curiosity.

I’ve done a few of these reflective pieces about things I wish I knew before my 30s but this is arguably up there with the most important thing I learned before 30.

Your life is allowed to change and so are you.

👋 Who are you again? I’m Karan Rajan - a doctor and curious explorer of all things health and wellness. I host the Dr Karan Explores Podcast and have written two books "This Book May Save Your Life" and "This Is Vital Information" (you can pre-order it now!) and have just founded a microbiome company, LOAM Science  to create the best fiber product in the world!

Every Sunday, I share 3 interesting things about health, life and science to make your life easier, healthier and happier. (Disclaimer: I’m more your friend with health benefits. None of this is medical advice.) 

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