Creatine - can this muscle-boosting supplement help boost my brain?

I have some in my cupboard. And I'm far from alone - creatine has become the supplement of choice for millions.

Originally known for enhancing the performance of bodybuilders and athletes in the 1990s, this white powder is now entering the spice cupboards (well, that's where I store mine) of women in their 40s.

It's arguably one of the world's most researched supplements. Thousands of studies have been carried out over the past few decades evaluating its ability to increase muscle mass and overall strength.

"Creatine has become so big, you feel that if you are not using it, you are kind of losing out," says Dr Henry Chung, a lecturer in sport and exercise science at the University of Essex. "It's moved from elite sport into the mainstream. It's not about whether to take it anymore, it's about when to take it - before or after exercise? Everyday? How much?

"In which form is best? Powder, tablets, gummies?"

Creatine is a naturally occurring compound which is stored in our muscles, and helps our cells produce energy. It is a vital component in the ATP-CP system, the fastest, most powerful energy system in our bodies.

It fuels the first 10-20 seconds in high intensity workouts - giving that quick, powerful burst of energy. From lifting weights to sprinting round the track, research suggests creatine supplementation can help improve performance.

And away from the gym, there is a growing, but still relatively limited, body of evidence to suggest it can also help with our short-term memory, mood and focus.

So, can this supplement improve our ability to think, remember and respond?

And for me, and many others, will it help clear our brain fog, a catch-all term that describes an inability to think clearly, string a sentence together, and remember the simplest of things?

For some people with serious post-viral conditions, brain fog can be longer term and potentially life-changing. If you have concerns, it is best to seek medical help.

For most, brain fog is usually temporary and can happen because of an illness or certain types of medical treatment. For millions of women, it can be a symptom of the perimenopause, due to hormonal fluctuations.

Katie Mansell believes creatine has helped in many parts of her life. The 46-year-old from Merseyside lifts weights, runs 30-40 miles a week, has a full-on job as the chief financial officer of a software company, and a busy home life with a teenage son and two dogs.

"A few months ago, I was out of sorts. I was finding training really hard work and I was struggling to focus on things," she says.

"It was my friend who recommended it - she said it was a game changer."

Katie, who is also perimenopausal, started taking six grams of creatine a day three months ago, and is beginning to feel a difference. Her mood feels a bit lighter, she can lift heavier weights and the fog that had descended on her brain has started to lift.

"I've got more motivation to do things, especially when it comes to training. I feel stronger when I'm lifting and bouldering, and I can also think more clearly."

Katie does caveat this - she's also on magnesium supplements and has started on hormone replacement therapy (HRT), but she's confident that creatine is making an impact and will continue with her daily dose.

There are others who believe it's made little difference and there is divided opinion on whether the majority of us get the amount of creatine we need through our diets. Katie, who is a vegetarian, says she was probably missing out. While it's understood our bodies produce one gram of it naturally, the rest comes from high-protein food like meat and fish.

The supplement's impact on male athletes has been documented since the early 1990s but, as with a lot of scientific research, female biology was missing from the equation.

"I used to have to guess what my female athletes needed," explains Dr Susan Kleiner, a high-performance nutritionist from the US state of Washington. "All the research was based on men."

It wasn't until a few years ago that women's hormonal fluctuations were taken into account, says Dr Kleiner, an adviser on the board of Creatine Health, a global initiative set up to promote research on the supplement. "And that was when scientists started to see a real impact in other parts of the body."

Instead of just concentrating on how creatine interacts with our muscles in a sport setting, scientists have begun to discover how it could potentially affect reproductive health, bone health and brain function - all of which can be affected during perimenopause, she explains.

So does that mean that creatine can help my brain fog?

"That's an interesting thought," says Professor Emeritus Trevor McMorris. "It might do."

Having been in the field for more than 40 years, he has carried out many studies into creatine supplementation.

He says perimenopausal brain fog could have a similar impact to sleep deprivation, something he has researched extensively, finding that high doses of creatine could mitigate the effects of too little sleep.

When people use the supplement, the brain may - like our muscles - increase its stores of creatine. This helps produce more energy, which could help improve memory and the ability to process information.

But Prof McMorris say it won't work for everyone. His most recent research suggests people need to be under a level of stress - for example, being sleep deprived or not having enough creatine in their diet - for it to make a difference.

So, in short, when it comes to helping me with my brain fog - maybe - there's potential. The experts I have spoken to believe it's an "an exciting time" in this line of research, but that more studies are needed.

Dietician Lucy Upton warns that we could start to see more side effects to creatine use because of the supplement's surge in popularity.

"While there is extensive research, that has been in a controlled environment," she says. "Now we need to think about the variation of body sizes, doses and any pre-existing conditions."

Currently, known side effects are the risk of stomach upset, muscle cramps and bloating. People with conditions affecting their kidneys should consult a doctor before taking it.

While Dr Chung sees no harm in healthy adults "trying it out", he also says results tend to be "minimal gains", adding that "it is not, by any means, a wonder drug".

As for me, I started taking the creatine in my cupboard but stopped after a month (blame it on the brain fog).

Perhaps I'll give it another try.