02/11/2025
Brain’s Night-time Antioxidant 💤
This night-time molecule is also one of the brain’s most powerful protectors – your night-time antioxidant – working while you rest, to defend neurons, restore energy and preserve clear thinking. Melatonin helps your brain clean up daily oxidative damage, regulate mood, and protect memory networks from ageing.
When levels drop – through stress, light exposure, age or caffeine – you don’t just lose sleep; you lose part of your brain’s natural repair system.
The Brain’s Nightly Repair Shift
Every night, while you rest, your brain goes to work. Waste is cleared away, cells are repaired, and antioxidants are replenished.
At the heart of this clean-up crew is melatonin, made in the pineal gland and the master conductor of your brain’s nocturnal activity.
It doesn’t just promote sleep; it powers the production of glutathione, the body and brain’s chief antioxidant and cellular shield. When melatonin levels fall, oxidative stress rises – accelerating neuronal ageing and the build-up of damaging amyloid and tau proteins, Why? Melatonin normally switches on the brain’s own antioxidant defences, recycling glutathione and neutralising free radicals inside mitochondria. Without enough melatonin, these reactive molecules (like amyloid and tau proteins) accumulate, inflaming brain tissue and allowing toxic proteins to clump together.
In studies, restoring melatonin reduced oxidative damage and slowed amyloid formation – a reminder that good sleep truly is brain repair in action.
Want to know what your current glutathione status is? Order your test here to find out
Light At Night Steals Your Brain’s Protection
Here’s the catch: melatonin only comes out when it’s dark.
Even modest evening light – the glow of your phone, TV, bedside lamp or standby light – can switch off its release.
That’s because the light-sensitive cells in your eyes, send a “daytime” signal to the brain’s master clock in the suprachiasmatic nucleus (a tiny region in the hypothalamus that controls your body’s sleep-wake rhythm) instantly halting melatonin production.
In clinical studies, exposure to ordinary indoor light before bedtime suppressed melatonin by up to 85 per cent and shortened its duration by several hours.
That’s why your late-night scroll or TV binge can leave you foggy and flat the next morning.
To support melatonin, you want to create a dark place to sleep. No lights on, heavy curtains, no street lamps. Using eye masks and utilising blue-light blocking glasses, software or filters can also be helpful if you know you are going to be on screens in the evening. You can even get special bulbs for bedside lamps or special lighting solutions for the bathroom for nighttime toilet trips.
Light is a powerful data input into the brain – so be mindful and protect yourself where practical and possible.
Age, Stress And Hormones Flatten The Rhythm
As time goes by, your natural melatonin rhythm starts to fade – by mid-life, your night-time levels can fall by half.
It’s one of many reasons why people can start waking up at night, struggle to drift off, or feel less refreshed after sleep.
For women, the hormonal rollercoaster of perimenopause makes things even trickier: falling oestrogen and progesterone throw the body clock off balance, making deep sleep harder just when the brain needs it most. (Learn more about how to support women’s hormones and brain health here.)
Melatonin levels don’t just impact sleep; studies show that lower melatonin is linked with poorer memory, mood dips and faster cognitive ageing. While melatonin is impacted by ageing, the good news is that it can be supported and restored.
Coffee vs. Melatonin – When Caffeine Steals Your Sleep Hormone
Caffeine doesn’t just keep you awake – it directly interferes with melatonin’s nightly rise.
Even a single espresso six hours before bed can delay melatonin release by up to 40 minutes and reduce total melatonin production by as much as 20%. (And don’t forget black and green tea and most energy drinks contain caffeine too.)
That’s because caffeine blocks adenosine receptors – the same system that tells the pineal gland it’s time for darkness and rest. When that signal is muted, the body’s internal clock (the suprachiasmatic nucleus) misreads the time and keeps you in ‘day-mode’ far longer than intended.
Avoid coffee (and other caffeine sources) after 12 p.m., especially if you have sleep or mood issues.
Choose herbal or decaf alternatives after lunch. If you’re sensitive, even morning caffeine can blunt night-time melatonin, so experiment with caffeine-free days and observe your sleep quality.
Melatonin and Mitochondria: Your Inner Night-Time Antioxidant Factory
Here’s where melatonin gets even more fascinating. It isn’t just released from the pineal gland at night, your brain cells actually produce it inside their mitochondria, the tiny engines that create energy (ATP) and power every thought and memory.
This is clever biology: the very place where energy is made – and where most oxidative stress occurs – also makes its own night-time antioxidant. Melatonin acts locally in the cell, mopping up the free radicals created as mitochondria burn fuel through the day, keeping these fragile energy factories running smoothly.
It doesn’t function only as a sleep hormone, made only in the pineal gland – it’s also made throughout your brain (and body’s) energy-producing mitochondria, where it acts as a built-in night-time antioxidant to protect them from damage.
This local production is what keeps your neurons energised and resilient – and why good, deep sleep is essential for restoring brain power and mental clarity. (And why disrupted or shallow sleep can leave you foggy the next morning!)Want more insight into how to support your brain through quality sleep? Join our next live webinar with our expert Sleep Scientist here.
How To Restore Your Natural Rhythm
While short-term melatonin supplements (0.5–3 mg) can improve sleep onset and quality in older adults and can be bought in North America or prescribed in the UK, the goal is to rebuild the body’s own rhythm:
Dark evenings, bright mornings – dim lights, avoid screens, use blue-light blocking technology, glasses and filters an hour before bed; get natural light soon after waking.
Avoid caffeine after 12 pm or if sleep is a real struggle – remove altogether, and see how it impacts your sleep.
Tryptophan-rich foods – turkey, oats, eggs and sunflower seeds support serotonin-to-melatonin conversion (with B6 and magnesium).
Keep bedrooms cool and quiet – a small temperature drop signals melatonin release.
Check in with your antioxidant status with the DRIfT test here.
Melatonin: Protecting Your Brain’s Night-time Antioxidant Rhythm
Melatonin is the nightly molecule that lets the brain rest, reset and renew itself.
Protecting your melatonin rhythm may be one of the simplest, most powerful preventative steps you can take to protect your memory.
