For the 3am wake-up that started in perimenopause.
Magnesium has more clinical sleep evidence than almost any other supplement you can buy without a prescription.
Three controlled trials · 17 minutes faster to sleep.
60 servings. Less than $0.94 per night
- 60-day money-back guarantee
- Third-party tested
- Next-day Auckland dispatch
It started with the sleep. Then everything else shifted.
Brain firing, body running hot, lying still in the dark. By 5am you've made a list of everything you forgot last week.
By 7am you're up, tired in a way coffee doesn't touch, deciding which of today's meetings you can fake your way through.
Most GPs will tell you it's stress. It isn't.
You are not imagining it. You are not doing something wrong.
One specific thing is happening in your body, and one of those symptoms has an answer backed by more clinical evidence than almost anything else you can buy without a prescription.
Oestrogen doesn't
fall. It crashes around.
For most women, the worst sleep happens in perimenopause, when oestrogen swings unpredictably from week to week. That's why your symptoms feel erratic. They are.
This is not stress. It's not a sleep hygiene problem. It's a neurochemical shift, and it doesn't reverse on its own.
Magnesium is how your body brakes.
It supports GABA signaling, the calming system your brain uses to wind down. It also helps regulate cortisol, the stress hormone that's supposed to drop at night but doesn't reliably drop anymore.
But for the sleep part, the clinical evidence is unusually specific.
What the trials actually found.
Three randomised controlled trials. Older adults with insomnia. Daily magnesium or placebo.
People taking magnesium fell asleep about 17 minutes faster than people taking a placebo.
That sounds small until you're the one lying awake. Over a week, it's almost two hours of sleep you didn't used to get.
Mah & Pitre, 2021. BMC Complementary Medicine & Therapies.
500mg magnesium daily, 8 weeks.
In older adults with insomnia, magnesium supplementation produced significant improvements in four sleep markers at once: faster sleep onset, reduced insomnia severity, higher melatonin, lower cortisol.
A recent chelated magnesium trial.
A 2025 trial using a chelated form of magnesium (bisglycinate) showed a modest but statistically significant improvement in insomnia scores. Biosphere uses a different chelate (lysinate glycinate) in the same family.
If you've tried magnesium
before and it didn't help.
The trials that moved sleep markers used 300 to 500mg of elemental magnesium a day. Most chemist magnesium is 150 to 250mg. A lower dose isn't a smaller version of the same effect. It's often below the threshold where any effect shows up at all.
Form matters too. Magnesium oxide, the cheapest and most common form, showed no difference from placebo in a randomised double-blind trial. Chelated forms (the kind bound to an amino acid) and citrate both raised blood magnesium meaningfully.
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New Zealand's most reviewed magnesium • 150+ stores nationwide
60-Day Money Back Guarantee
If you don't feel a difference, you get every dollar back. No forms. No questions asked. Just email us.
Three bioavailable magnesium forms at the dose that actually works.
Less than $0.94 per night. Two months supply
Choose your flavour:
- Third-party tested every batch
- Naturally sweetened with monk fruit and stevia
- Vegan, gluten-free, no allergens
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New Zealand's most reviewed magnesium · 150+ stores nationwide
60 Nights to Decide
Try Biosphere Magnesium for 60 nights. If your sleep hasn't changed, email us. We'll refund you in full. No forms, no returns.
- Full refund within 48 hours of your email
- No questions asked
- Keep the tub either way
- 60-night money-back guarantee
- Third-party tested
- Next-day Auckland dispatch
Before You Order
Will this actually help if my main issue is menopause, not just sleep?
Magnesium works on two of the sleep systems oestrogen disrupts: GABA signaling and cortisol rhythm. It doesn't fix hot flushes or reverse menopause. What it does is give you back the body chemistry that lets you wind down and stay asleep. For the sleep part, that's where the strongest evidence sits.
How long before I notice anything?
Most women notice shifts within one to two weeks. Full effect builds over about four weeks. The clinical trial we cite used daily magnesium for eight weeks. If nothing has changed by week four, the 60-night guarantee has you covered.
Can I take this with HRT, sleep medication, or antidepressants?
Check with your GP before combining any supplement with prescription medication, including HRT. Magnesium is generally well-tolerated alongside most prescriptions, but your doctor knows your full picture. Standard advice, not a red flag about the product.
Will it make me groggy in the morning?
No. Magnesium isn't a sedative. It supports the systems that let your body wind down on its own, so there's no next-day hangover. Different from melatonin. Very different from prescription sleep aids.
Can I take this every night, indefinitely?
Yes. Magnesium isn't habit-forming. Your body doesn't build tolerance the way it does with sleep medication, and any excess is excreted in urine. It's a mineral, not a drug, so there's no need to cycle off or take breaks. Most of our customers take it nightly for months or years. If you have kidney disease or take prescription medication, check with your GP before starting.
Menopause is the transition.
Sleep is the first thing worth getting back.
You've read the mechanism. You've seen the evidence. You know what magnesium does and what it doesn't. The only thing left is 60 nights to find out.
- 60-night money-back guarantee
- Next-day Auckland dispatch