What changed
Magnesium glycinate about $63.3M a month on Amazon, up 85.7%; supplements about $1.3B a month, up 40%
When
Market Defense report published September 16, 2026, three months of data
Who it affects
Supplement brands and sellers on Amazon and TikTok Shop
What to do
Check form, dose and count against search demand, then set bids from margin

Key takeaways

  • Market Defense puts Amazon magnesium glycinate at about $63.3M a month, up 85.7%, nearly 5% of a $1.3B a month supplements category.
  • On a yearly basis that estimate is larger than SPINS measured for all magnesium in US natural and conventional stores, so Amazon is where the growth is.
  • Listings are multiplying, so win on form, dose and count terms and set bids from margin, not from the headline growth.

Amazon supplements, Summer 2026

$1.3Bsupplements per month
+40%category growth YoY
$63.3Mmagnesium glycinate per month
+85.7%glycinate growth
Source: Market Defense, September 2026

What the data shows

Market Defense, a marketplace agency, calls magnesium the anchor of the Amazon supplements category in its Summer 2026 report. Its public summary gives magnesium glycinate at $63.3 million a month, up 85.7%, inside a category of about $1.3 billion a month growing 40% year over year. Simple division puts glycinate at just under 5% of all Amazon supplement sales. The report says it also ranks the top 15 brands by share, but that list sits behind a download form, so we do not repeat any brand ranking here.

The trend shows up outside Amazon too. In a ConsumerLab survey of more than 8,850 regular supplement users, published February 26, 2026, magnesium was used by 64.8% of respondents, up 5.3 points, second only to vitamin D. In the UK, NutraIngredients reported on November 3, 2026 that magnesium was the top search on Holland & Barrett's website in 2026, at 32.8 million searches, and that its own magnesium bisglycinate was its best seller at almost 45 million capsules.

Amazon is pulling ahead of stores

SPINS, in its 2026 trend predictions, measured magnesium supplements at $453 million, up 17.1%, across US natural and conventional stores for the 52 weeks ending October 5, 2025. That data source does not include Amazon. If Market Defense's monthly glycinate figure held for a full year, it would be about $760 million, more than SPINS measured for every form of magnesium in those stores.

The two numbers come from different firms, periods and methods, so read this as direction, not a precise ranking. But both point the same way: glycinate growth on Amazon is several times the store growth rate. Modern Retail reported in February that supplier Solaray grew its magnesium segment 16.55% in 2025 and has run triple shifts since late 2023, and that the number of online stores selling products with magnesium in the title rose 500% in six months, per PrettyDamnQuick data. That last figure counts listings, not sales, and it is the warning sign: supply is chasing demand fast.

Magnesium growth by channel

  • Amazon glycinate (Market Defense)85.7%
  • US stores, all magnesium (SPINS)17.1%
  • Solaray magnesium 202516.55%
Source: Market Defense 2026; SPINS 2026; Modern Retail 2026

TikTok Shop is the second front

Market Defense says supplement buyers spend about $98 a year on TikTok Shop against $236 on Amazon. On TikTok Shop, analytics firm FastMoss estimates a magnesium complex product from Toplux was the number two product by revenue in the US in Q3 2026, at about $8.2 million, and the top seller by units, though its monthly units fell from about 175,000 in July to about 108,000 in September. Those are third party estimates, but they show how quickly a social spike can rise and cool.

So what: growth is real, the margin is not guaranteed

A category growing near 86% attracts new listings, and new listings raise click costs on the head terms. The money is in the details shoppers search for: form (glycinate, citrate, threonate), dose per serving, capsule count and use cases such as sleep or muscle cramps.

For example, using illustrative numbers: a $24.99 glycinate bottle with a $5.00 landed cost and about $10.50 in referral and FBA fees leaves about $9.49 before ads, so break-even ACoS is about 38%. If competition pushes the cost per click on the main term to $2.00 at a 10% conversion rate, ad cost per order is $20.00, or 80% ACoS, a loss on every ad sale. A long tail term at $0.80 and 12% conversion costs $6.67 per order, a 27% ACoS that keeps the product profitable.

What sellers should do

Use this list if you sell or plan to launch a magnesium product. Check our creatine boom coverage for the same pattern in a neighbouring line.

  • Category manager: pull the last 90 days of magnesium terms in Brand Analytics Search Query Performance and group them by form, dose and use. Metric: share of clicks you win on each group.
  • PPC manager: set target ACoS from margin after fees with our Amazon PPC management approach, and move spend from head terms to exact match long tail terms that convert. Metric: blended ACoS below break-even.
  • Product lead: validate a gap, such as a capsule count or form the top listings miss, using Amazon product research before ordering stock. Metric: search volume per competing listing for that gap.
  • Compliance lead: confirm testing and label rules under the Amazon dietary supplement policy before launch, since supplements need verification and claims are policed. Metric: zero listing suppressions in Account Health.
  • Ops lead: plan inventory for a demand curve that can cool, as the TikTok Shop data shows. Metric: weeks of cover between 6 and 10 in the FBA Inventory page.
  • Brand owner: if you already rank, defend your brand name and best converting terms with Sponsored Brands. Metric: top of search impression share on your brand terms.

Before you launch a magnesium SKU

  • Group search terms by form, dose, count
  • Model break-even ACoS after fees
  • Find a gap the top listings miss
  • Confirm supplement testing and label rules
  • Plan stock for a cooling curve
  • Defend brand terms with Sponsored Brands

When this does not apply

If you sell a single mineral at a low price point with no clear edge, the growth figures do not make your listing viable; copycats and price cuts will. The Market Defense numbers are an agency estimate from three months of data, not Amazon disclosures, and cannot tell you any one brand's sales. Outside the US, Holland & Barrett's data shows interest, but not Amazon demand.

Where PPC Spider helps

We track category shifts like this on our ecommerce marketplace news channel. SpiderOS watches bids, budgets, search terms and stock every day, and we set target ACoS from product margin after fees. To see where your supplement listings are leaking money, start with a free Amazon audit.

Sources

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