10 Best Magnesium Supplements in New Zealand: Most Popular Picks Ranked for 2026

Finding a good magnesium supplement in New Zealand is harder than it should be. Some products list impressive numbers on the front of the bottle, but deliver far less usable magnesium than you'd think. Others rely on cheap, poorly absorbed forms like oxide and dress it up with multi-form marketing. Only very few brands tell you what's in the product with independent testing to back it up.

We took the ten most popular magnesium supplements in New Zealand and ranked them on what matters: the form of magnesium used, how much elemental (usable) magnesium you get per serve, and cost per 100 mg, so you can compare fairly regardless of your individual dose needs.

Some of these products are excellent. Others are popular for the wrong reasons. The comparison table below has the essentials. The full breakdown of each product follows.

10 Most Popular Magnesium Supplements in New Zealand at a Glance

All prices are RRP in NZD as of early 2026. Cost per 100 mg of elemental magnesium lets you compare value regardless of how much magnesium any person needs to take.

How We Rate Magnesium Supplements

Not all magnesium supplements are equal, and the label on the front of the bottle rarely tells the full story. Here's what we look at.

Absorption and Bioavailability

The form of magnesium determines how much your body can use. Chelated forms like glycinate, citrate, and malate are bound to amino acids or organic compounds, which allows them to pass through the gut wall more efficiently.

Marine magnesium and magnesium oxide are cheaper to produce but absorb poorly, with oxide showing as little as 4% bioavailability in some studies. If a product relies heavily on oxide, it doesn't matter how many milligrams are on the label.

Elemental Magnesium per Dose

This is the number that counts. "Magnesium 800" or "Magnesium 625" might sound impressive, but these numbers often refer to total compound weight, not the usable elemental magnesium.

Always check the elemental magnesium figure on the back label. For most adults, an effective daily dose sits between 300 and 600 mg of elemental magnesium, depending on body weight and individual needs.

Tolerance and Gut Comfort

Certain forms are notorious for causing loose stools. Citrate and oxide are the main offenders at higher doses. Glycinate is generally the gentlest option, which is why it's preferred for people who need larger doses without digestive issues.

Products that blend multiple forms can spread the gut load across different absorption pathways, reducing the chance of discomfort at therapeutic doses.

Ingredient Quality

Some supplements include useful cofactors like vitamin B6, taurine, or L-carnitine that genuinely support magnesium metabolism or energy production. Others pad their formulas with fillers. We look at what's beyond the magnesium itself and whether those extras actually serve a purpose.

Also read: Magnesium for Muscle Recovery

Manufacturing and Testing

We look at whether the product is manufactured in a GMP-certified facility and whether the brand has independent testing to verify label claims. Publishing a Certificate of Analysis (CoA) is above and beyond what most brands do, but it's a meaningful trust signal when a company makes its testing results publicly available.

Value for Money

Price per bottle is misleading when serving sizes and doses vary wildly. We use cost per 100 mg of elemental magnesium, which gives a fair comparison regardless of how much any individual person needs. A $42 bottle with 125 mg per cap is not necessarily cheaper than a $70 bottle delivering 400 mg per serve once you do the maths.

Most Popular Magnesium Supplements in New Zealand Ranked for 2026

Pick #1: Biosphere Nutrition Magnesium (Best Overall)

The formula uses three forms of magnesium, each contributing to the 400 mg total through a different absorption pathway. Magnesium Lysinate Glycinate Chelate provides 100 mg of elemental magnesium from 1,000 mg of compound.

It's a chelated form bound to both lysine and glycine, designed for high bioavailability and gentle digestion. Magnesium Citrate provides 150 mg of elemental magnesium from 1,000 mg of the compound.

Citrate is one of the most researched forms with strong absorption data. DiMagnesium Malate provides the remaining 150 mg of elemental magnesium from 750 mg of compound. Malate is preferred for energy production and muscle support.

The triple blend matters because it reduces the chance of gut discomfort at higher doses. Single-form products that deliver 400 mg from citrate alone can cause loose stools in a lot of people. Spreading the load across three forms with different absorption mechanisms is a practical solution.

Biosphere publishes a Certificate of Analysis on their product page, meaning an independent lab has verified the contents match the label. That's unusual in the NZ supplement market. Most brands ask you to trust the label. This one shows you the lab results.

At 60 serves per container, you're getting two months of supply. Other ingredients are minimal: citric acid, natural flavours, monk fruit extract, stevia leaf extract, and beta carotene with turmeric for colour. No artificial sweeteners, no fillers.

Pick #2: BioBalance Magnesium Glycinate High Dose (Best Value Capsule)

This delivers 300 mg of elemental magnesium from bisglycinate in a single capsule, which is a strong dose for the form. The inclusion of P5P (pyridoxal-5-phosphate, the activated form of vitamin B6) at 5.5 mg is a useful addition. P5P is a cofactor that supports magnesium absorption and utilisation.

Other ingredients are just silica, magnesium stearate, and the HPMC capsule shell.

At $0.16 per 100 mg, this is the best value chelated magnesium on the NZ market by a wide margin. The 300 mg dose works well for general supplementation but may leave a gap for people over 75 kg or those dealing with deficiency symptoms.

Adding a second capsule to reach 600 mg still keeps the daily cost well under $1, and 120 capsules means the bottle lasts two to four months depending on your dose. If budget matters and you prefer capsules over powder, this is hard to beat.

Pick #3: Solgar Magnesium Citrate (Best Pure Citrate)

Citrate is one of the most researched forms of magnesium with strong bioavailability data. At 400 mg elemental per two-tablet serve, this is a full therapeutic dose from a single well-absorbed form.

The value at $0.28 per 100 mg is competitive. The ingredient list is clean: magnesium citrate with standard tableting aids (microcrystalline cellulose, dicalcium phosphate, silicon dioxide, vegetable magnesium stearate, and cellulose-based glazing agents).

The trade-off with citrate is gut tolerance. At higher doses, citrate has a laxative effect that bothers some people, particularly those who already tend towards loose stools.

If that's you, glycinate is the gentler option. The tablet format is also larger than average, and some people find them harder to swallow. At 30 serves per bottle, you're buying monthly. Available at Life Pharmacy, Unichem, and most independent NZ pharmacies.

Pick #4: Nutra-Life Magnesium Glycinate High Strength Powder (Best NZ-Made Powder)

The formula is straightforward: 350 mg of elemental magnesium from glycinate per scoop, plus 200 mg of vitamin C. Glycinate is well absorbed and gentle on the stomach, and 350 mg per serve is a solid therapeutic dose.

Other ingredients include natural flavours, sweeteners (glucose and thaumatin), acidity regulators, and a bulking agent. Contains sulfites.

The 360 g tub provides 60 serves, matching Biosphere for supply length. The per-milligram cost of $0.47 per 100 mg is notably higher than Biosphere ($0.29) despite delivering 50 mg less per serve and using a single form rather than a triple blend.

A smaller 180 g tub (30 serves) is also available at $60.99 RRP, though the larger tub is better value per serve.

Pick #5: BePure Magnesium Restore

The formula provides 300 mg of elemental magnesium from bisglycinate per two-capsule serving, with 100 mg of L-carnitine for energy support. The ingredient list is clean: cellulose, vegetable stearate, rice concentrate, and silica as excipients. Bisglycinate is a well-absorbed form that's gentle on the stomach, and L-carnitine plays a role in fatty acid metabolism and energy production.

The 300 mg dose is adequate for general supplementation but falls short for people with higher requirements. At $0.33 per 100 mg, this is more than double the per-milligram cost of BioBalance ($0.16), which delivers the same form and the same dose per serve.

The L-carnitine is the differentiator. If that matters to you, the premium might be worth it. If you're primarily after magnesium bisglycinate, BioBalance gives you the same thing with better value and a useful B6 cofactor.

Pick #6: Ethical Nutrients Mega Magnesium Powder (Best Cofactor Formula)

MetaMag is a proprietary magnesium diglycinate that absorbs well and is gentle on the stomach. But the real selling point is the cofactor profile: each serving includes 3 g of taurine (supports cardiovascular function and may enhance magnesium uptake), 300 mg of vitamin C, 68 mg of calcium, 52 mg of potassium, and 50 mg of vitamin B6. That's the most comprehensive formula on this list.

The trade-off is cost. At $0.66 per 100 mg, this is the second most expensive product on the list per milligram of magnesium (behind the liposomal option). You're paying for the extra ingredients and the MetaMag branding. The 450 g tub provides around 51 serves, which is reasonable.

If you want a magnesium powder with a full cofactor suite and don't mind the price, this delivers. If you mainly need magnesium and can get your taurine, B6, and vitamin C elsewhere, you'd be better off with a cheaper option and separate supplements.

Pick #7: Clinicians Magnesium 625 (Budget Capsule)

The "625" refers to the total compound weight of the magnesium aspartate complex, not the elemental magnesium, which is 125 mg per capsule. That naming catches people out.

Aspartate is a reasonably well-absorbed form, though it doesn't have the same depth of research as glycinate for sleep or citrate for cramps specifically. The formula is bare bones: magnesium aspartate and magnesium stearate, nothing else.

At $0.19 per 100 mg, the value is solid. The main downside is pill burden: you'd need three capsules daily to reach 375 mg, or four for 500 mg. A 180-capsule bottle lasts 45 to 60 days depending on your dose. If you're comfortable taking multiple caps a day and want to keep costs low, this does the job.

Pick #8: BioBalance Liposomal Magnesium (Best Liposomal Option)

This is the only liposomal magnesium on the list, and it's a genuinely different delivery mechanism. Liposomal delivery wraps the magnesium in phospholipid spheres (phosphatidylcholine from non-GMO sunflower oil), designed to protect the mineral through digestion and improve cellular uptake.

The technology has solid evidence behind it for nutrients like vitamin C, and the same principles apply here.

The formula uses three forms of magnesium (beta hydroxybutyrate, glycerophosphate, and bisglycinate) plus 50 mg of choline and hyaluronic acid. The BHB form is notable because it may offer additional benefits for energy and ketone production. The liquid format avoids swallowing capsules entirely, and the 1,000 mg phosphatidylcholine complex acts as both the delivery system and a source of choline.

At $1.08 per 100 mg, this is by far the most expensive magnesium on the list. The 200 mg elemental dose is also the lowest, which means most adults would need additional magnesium from another source to reach therapeutic levels. This isn't a cost-effective way to hit your daily target.

It's a premium absorption play for people who've tried standard forms and found them inadequate, or who have digestive issues that limit absorption of conventional supplements.

Pick #9: Go Healthy Magnesium 1-A-Day (Highest Claimed Dose)

This claims 500 mg of elemental magnesium from a natural marine source in a single capsule. On paper, that's the highest dose and one of the lowest costs per 100 mg on the list.

The product also contains naturally occurring trace minerals, including boron, calcium, chromium, copper, iodine, iron, manganese, potassium, selenium, and zinc.

The question is how much of that 500 mg your body absorbs. Marine magnesium is sourced from seawater and typically contains a mix of magnesium compounds.

Without the brand disclosing the specific breakdown of forms within the marine blend, it's difficult to assess true bioavailability. Marine sources can include hydroxide and carbonate alongside more absorbable forms.

If the marine magnesium absorbs at even half the rate of chelated glycinate, the effective dose drops considerably, and the real cost per 100 mg of absorbed magnesium is significantly higher than $0.17.

Pick #10: Go Healthy Magnesium 800 (Misleading Label)

This product markets itself as containing "four forms of Magnesium to help increase absorption and bioavailability." That sounds good until you check what those four forms contribute.

Of the 360 mg elemental magnesium per capsule, 300 mg (83%) comes from magnesium oxide. The remaining 60 mg is split across aspartate, amino acid chelate, and citrate at just 20 mg each.

Magnesium oxide absorbs at around 4% in most studies. If the oxide portion delivers 4% to your bloodstream, that's roughly 12 mg of usable magnesium from 300 mg of oxide.

Add the 60 mg from the three better-absorbed forms, and you could be looking at perhaps 70 to 80 mg of absorbed magnesium from a capsule that claims 360 mg. The three additional forms exist in such small amounts that they function more as marketing than meaningful absorption pathways.

The "800" in the product name doesn't refer to the elemental magnesium (360 mg) or the total compound weight (660 mg). It appears to be a marketing number with no clear basis.

At $0.21 per 100 mg on paper, this looks like a decent value, but the real cost per 100 mg of absorbed magnesium is dramatically higher. This is a textbook example of why checking the back label matters more than the front.

Who Should Talk to a Professional First? 

Magnesium is generally well tolerated, but some people should check with their GP or pharmacist before starting. This includes anyone taking blood pressure medication, heart medication, antibiotics, or bisphosphonates for osteoporosis.

Magnesium can interact with these medications by affecting absorption timing. If you have kidney disease, magnesium supplementation requires medical supervision because your kidneys regulate how much magnesium stays in your body.

For more on potential interactions, see our guide to magnesium side effects.

The Bottom Line

Biosphere Nutrition Magnesium takes our top spot because it ticks every box: a full 400 mg therapeutic dose from three bioavailable forms (lysinate glycinate chelate, citrate, and malate), a two-month supply, and published third-party testing. At $0.29 per 100 mg, it's priced competitively against products that deliver less.

BioBalance Magnesium Glycinate is the best value capsule at $0.16 per 100 mg from quality bisglycinate. Solgar Magnesium Citrate delivers a full 400 mg therapeutic dose at $0.28 per 100 mg. BePure is a clean formula, though the per-milligram cost is hard to justify against BioBalance offering the same form at half the price.

Ethical Nutrients has the most comprehensive cofactor formula but you pay for it. BioBalance Liposomal is worth considering if standard forms haven't worked for you. Clinicians 625 is a dependable budget option if you don't mind the pill burden.

The products to avoid are those that rely on magnesium oxide while marketing themselves as high-dose or multi-form. The Go Healthy Magnesium 800 is a clear example: 83% oxide, dressed up as a four-form product. At that point you're paying for a label, not a result.

Whatever you choose: check the elemental magnesium figure (not the compound weight), choose a chelated form over oxide or unspecified marine blends, and understand how much you actually need based on your body weight.

For more on the benefits of magnesium supplementation, explore our guides.

How Much Magnesium Should I Take Daily?

A useful target is 7 to 10 mg of magnesium per kilogram of body weight per day. For a 70 kg person, that's 490 to 700 mg daily from food and supplements combined. The lower end suits healthy people with no specific symptoms.

The higher end is better for people dealing with poor sleep, muscle cramps, stress, or high training loads. Government RDAs (310 to 420 mg for adults) represent the minimum to prevent deficiency, not the amount needed for optimal function. Our magnesium dosage guide breaks this down in more detail with a calculator based on body weight.

Is Magnesium Glycinate Better Than Citrate?

Both are well-absorbed chelated forms, but they suit different needs. Glycinate is the gentlest on the stomach and has a calming effect that makes it the preferred choice for sleep and anxiety. Citrate is better researched for muscle cramps and has a mild laxative effect at higher doses, which can be helpful for people with constipation. A blend of both gives you the advantages of each form. Oxide is the one to avoid: it absorbs poorly (around 4%) and is mainly useful as a laxative.

Why Do Some Magnesium Supplements Look Cheaper but Deliver Less?

It comes down to elemental magnesium versus compound weight. A product labelled "Magnesium 625 mg" might only contain 125 mg of actual (elemental) magnesium.

The rest is the amino acid or compound it's bound to. That means you need three or four capsules to reach the same dose as a product delivering 400 mg per serve. When you calculate cost per 100 mg of usable magnesium, the "cheap" option often costs the same or more.

Why Does Magnesium Form Matter More Than Dose?

Because your body can only use what it absorbs. Magnesium oxide delivers roughly 4% of its elemental magnesium into your bloodstream. A capsule claiming 300 mg from oxide might realistically deliver 12 mg. Meanwhile, glycinate and citrate absorb significantly better.

A product with 300 mg from glycinate will deliver far more usable magnesium than a product with 500 mg from oxide. This is why cost per 100 mg needs to be considered alongside the form being used.

What Does Cost per 100 mg Actually Tell You?

Everyone's magnesium needs differ depending on body weight, activity level, and health goals. Comparing products on "cost per day" is misleading because a product with a lower daily dose looks cheaper per day, but you might need to take more of it. Cost per 100 mg of elemental magnesium gives you a standardised way to compare how much usable magnesium your money is buying, regardless of how much you individually need.

What Is Liposomal Magnesium?

Liposomal supplements wrap the active ingredient in tiny phospholipid spheres that protect it through digestion and may improve cellular uptake. The technology has good evidence for some nutrients, particularly vitamin C.

For magnesium, the theoretical advantage is bypassing the gut absorption limitations that affect standard forms. The trade-off is cost: liposomal products are significantly more expensive per milligram. They're best suited for people who've tried standard forms and had absorption or tolerance issues.

Medical Disclaimer

This article is for informational purposes only and does not constitute medical advice. Magnesium supplements can interact with certain medications. Consult your GP or pharmacist before starting any new supplement, particularly if you are pregnant, breastfeeding, or taking prescription medication.