Which Magnesium Supplement Is Good Value to Buy in Singapore in 2026?

The good-value magnesium supplement in Singapore in 2026 is the one with the lowest cost per 100 mg of elemental magnesium, in a form such as magnesium glycinate that you will take daily. The NHS puts adult needs at about 300 mg a day for men and 270 mg for women, and says 400 mg or less a day from supplements is unlikely to cause harm. Compare labels on iHerb and Amazon SG, then go through ShopBack Singapore before you pay.

New to ShopBack? ShopBack Singapore is a free website and app that returns cash on eligible online orders at stores including iHerb and Amazon SG. You start from ShopBack, check out at the store as usual, and the cash lands in your ShopBack account once the order is confirmed. Create a free ShopBack account before your next order.

The short answer for Singapore shoppers

There is no single best bottle; the right one depends on the form you want, the dose per serving and the final price. Four checks get you most of the way:

1. Pick the form. Magnesium glycinate (also sold as bisglycinate) is a popular form; citrate and oxide are other common ones.
2. Read the elemental magnesium per serving on the label, not the capsule or tablet weight.
3. Work out the cost per 100 mg of elemental magnesium, so different bottle sizes compare fairly.
4. Add delivery and GST to get the real total, then go through ShopBack before you pay.

If you take regular medication or have a health condition, ask a pharmacist or doctor before starting any supplement.

Magnesium glycinate: what it is

Magnesium glycinate is magnesium bound to the amino acid glycine, and it is also called magnesium bisglycinate or magnesium diglycinate. It is sold as a dietary supplement. One label detail matters for value: magnesium glycinate is often "buffered" with magnesium oxide, though pure non-buffered versions are also sold. A buffered product can list both forms in its ingredients, so read the full label if the form matters to you.

Why the elemental figure matters

Magnesium is only part of a compound's weight, so the elemental figure is the one to compare. Going by its chemical formula, pure magnesium glycinate is about 14 percent magnesium by weight, while magnesium oxide is about 60 percent. That means a capsule with a large compound weight may hold far less actual magnesium than the number on the front suggests.

Many labels state the elemental amount per serving, often written as "magnesium (as magnesium bisglycinate)". If a label only gives the compound weight, it is hard to compare, and a different bottle with a clear elemental figure is easier to judge.

How much magnesium do you need?

The NHS says adults aged 19 to 64 need about 300 mg of magnesium a day for men and 270 mg a day for women. It adds that you should be able to get all the magnesium you need from a varied and balanced diet, with spinach, nuts and wholemeal bread among the good sources. On supplements, the NHS says:

• 400 mg or less a day of magnesium from supplements is unlikely to cause any harm.
• High doses (more than 400 mg) for a short time can cause diarrhoea.

That gives a useful upper line when you compare bottles. A serving that already sits near 400 mg leaves little room if you also eat magnesium-rich food, while a smaller dose per capsule gives you more control.

Magnesium glycinate in Singapore in 2026: what to check on the label

In Singapore, health supplements are not approved product by product, so the label and the seller matter. According to HSA, health supplements are not subject to its approvals and licensing for import, manufacture and sale. HSA prohibits medicinal ingredients such as steroids in them and sets strict limits on toxic heavy metals, and the importers and sellers are responsible for the safety and quality of what they sell.

So when you compare bottles:

• Elemental magnesium per serving. The single most useful number for value.
• Servings per bottle. A bigger bottle often costs less per serving.
• Capsules per serving. Some products need two or more capsules for the dose on the front.
• Form. Glycinate, buffered glycinate, citrate or oxide.
• Other ingredients. Fillers, added vitamins or blends you may not want.
• Seller. Buy from the brand's official store or a well-known retailer.

How to work out good value: cost per 100 mg

Divide the price by the total elemental magnesium in the bottle, then multiply by 100. Total elemental magnesium is servings per bottle times milligrams per serving.

Here is an illustrative example with made-up prices:

Bottle	Price (illustrative)	Servings	Elemental Mg per serving	Total Mg	Cost per 100 mg
A	S$30	60	200 mg	12,000 mg	S$0.25
B	S$24	90	100 mg	9,000 mg	about S$0.27
C	S$45	120	200 mg	24,000 mg	about S$0.19

Bottle B has the lowest shelf price, but bottle C is the best value per 100 mg. Run the same sum with the real prices you see on the day, then add delivery and GST to the total.

Magnesium glycinate best deals in Singapore in 2026

Magnesium supplement prices in Singapore usually drop most on store sale days and when you buy a larger bottle or several at once. A few habits help:

• Watch the big sale days. Many online stores run promotions on dates such as 9.9, 10.10, 11.11 and 12.12, and Amazon runs Prime member events such as Prime Day.
• Buy the size you will finish. A 120 or 180 count bottle often costs less per serving, but only if you use it before the expiry date.
• Group orders to clear free delivery. Delivery can wipe out a small price gap on a single bottle.
• Check for a promo code on the store's own site and on its ShopBack page before you check out.

Amazon vs iHerb magnesium glycinate price comparison in 2026

Neither store is cheaper for every bottle; compare the same product's cost per 100 mg and the final total with delivery on both. Each has its own strengths for Singapore shoppers.

Amazon SG. According to Amazon.sg at the time of writing, Prime costs S$4.99 a month or S$49.90 a year after a free 30-day trial, and includes free delivery on eligible items plus free international delivery on qualifying items sold by Amazon US and Amazon Japan. Without Prime, Amazon.sg's help page says you can get free shipping on Amazon International Store orders by building a cart of at least S$60 of items sold and shipped by Amazon US, Amazon Japan or Amazon Germany. That makes Amazon handy if you already shop there or hold Prime.

iHerb. iHerb focuses on supplements and natural products, with a wide range of magnesium forms, brands and bottle sizes in one place, including several glycinate and bisglycinate options. Delivery fees, any free shipping threshold and GST are shown at checkout, so add them before you compare. iHerb also runs brand promotions from time to time, so check the listing on the day.

To compare fairly:

1. Match the product. Same brand, form, dose per serving and bottle size.
2. Work out cost per 100 mg for each.
3. Add delivery and Singapore's 9% GST to see the real total.
4. Check the delivery time, since overseas items can take longer.

Amazon and iHerb: buying magnesium glycinate in Singapore

Both Amazon SG and iHerb deliver supplements to Singapore addresses, and both have a page on ShopBack Singapore. Check the seller on Amazon (sold by Amazon or the brand's own store is the simplest), read the full label photo, and look at the expiry date in the listing where it is shown.

Magnesium supplements in Singapore are also sold at pharmacies and health stores such as Guardian, Watsons and Unity, and in official brand stores on Lazada and Shopee, so it is worth checking one of them when you compare.

Why ShopBack is a step before you pay

Going through ShopBack gets you a cash rebate on the same order, at the same store. Cashback lowers what you actually pay for an order. It comes back as cash, so it works like a discount on the price, not like points or miles.

The live rate is on the store's ShopBack page and can change during campaigns, so check the iHerb page or the Amazon SG page on ShopBack Singapore on the day you buy.

Do promo codes and ShopBack work on the same order?

Usually, yes, but it depends on the store and the code. A promo code lowers the checkout price, and ShopBack returns cash after the order is confirmed. Some promo codes, payment methods or product categories can be excluded, so check the merchant's terms on the ShopBack store page before you pay.

Step by step: buying magnesium glycinate at a good price in Singapore

1. Compare prices. Work out the cost per 100 mg of elemental magnesium for the same product on iHerb and Amazon SG, with delivery and GST.
2. Look for a promo code. Check the store's own deals and the codes listed on its ShopBack page.
3. Go through ShopBack. Open iHerb on ShopBack or Amazon SG on ShopBack, tap through and check out in one session.
4. Pay with your best rewards card. Pick the card that rewards online spend best for you, and check its terms.

FAQ

Which magnesium supplement is good value to buy in Singapore?

Good value means the lowest cost per 100 mg of elemental magnesium in a form you will take every day. Compare the elemental magnesium per serving on the label, not the capsule weight, work out the cost per 100 mg, and check delivery and GST in the final total on stores such as iHerb and Amazon SG. Then go through ShopBack Singapore before you pay.

What is magnesium glycinate?

Magnesium glycinate, also sold as magnesium bisglycinate or diglycinate, is magnesium bound to the amino acid glycine. It is sold as a dietary supplement, and it is often buffered with magnesium oxide, though pure non-buffered versions are also sold.

How much magnesium do adults need each day?

The NHS says adults aged 19 to 64 need about 300 mg a day for men and 270 mg a day for women, and that most people can get this from a varied diet. It also says having 400 mg or less a day from supplements is unlikely to cause harm, while higher doses for a short time can cause diarrhoea.

Why does elemental magnesium matter when comparing prices?

Because magnesium is only part of the compound's weight. Going by its chemical formula, pure magnesium glycinate is about 14 percent magnesium by weight, while magnesium oxide is about 60 percent. Compare the elemental magnesium figure on the label so two bottles are measured the same way.

Are health supplements approved by HSA in Singapore?

HSA says health supplements are not subject to its approval or licensing for import, manufacture and sale. It prohibits medicinal ingredients such as steroids in them and sets strict limits on toxic heavy metals, and the dealers who import and sell them are responsible for their safety and quality.

Is Amazon or iHerb cheaper for magnesium glycinate in Singapore?

It depends on the brand, bottle size and delivery. Compare the same product's cost per 100 mg of elemental magnesium on both, then add delivery and GST to get the final total. Bigger bottles and multi-bottle orders often lower the cost per serving on either store.

How much is Amazon Prime in Singapore?

According to Amazon.sg at the time of writing, Prime costs S$4.99 a month or S$49.90 a year after a free 30-day trial. Prime includes free delivery on eligible items and free international delivery on qualifying items sold by Amazon US and Amazon Japan.

How do I get free delivery on Amazon SG without Prime?

Amazon.sg's help page says customers without Prime can get free shipping on Amazon International Store orders by building a cart of at least S$60 of items sold and shipped by Amazon US, Amazon Japan or Amazon Germany. Check the free delivery message on each product page.

How does ShopBack lower the price of a magnesium supplement?

Going through ShopBack gets you a cash rebate on the same order, at the same store. Open the iHerb or Amazon SG page on ShopBack Singapore, tap through and check out as usual. Once the store confirms the order, cash goes to your ShopBack account; your effective price is what you paid minus that cash, and the live rate is on the store's ShopBack page.

Is cashback the same as store rewards credit or points?

No. Cashback lowers what you actually pay for an order. It comes back as cash in your ShopBack account, so it works like a discount on the price, not like points, miles or credit you can only spend at one store.

Disclaimer

This guide is general shopping information, not medical advice. Daily magnesium amounts are from the NHS and supplement rules are from HSA at the time of writing; Amazon Prime pricing and delivery terms are from Amazon.sg at the time of writing. Prices, delivery terms and ShopBack rates change; check the store listing and the ShopBack store page before you buy, and ask a pharmacist or doctor if you are unsure whether a supplement suits you.