What magnesium costs per day for a rugby player

By Tom Francis·Updated 2026-09-03·3 sources·Editorial policy

The calculation

Three numbers and one division. Pack price. Capsules in the pack. Capsules per serving. Divide the second by the third for servings, then divide the price by that.

Futuro Labs Magnesium Glycinate, 180 capsule tub: 19.99 pounds, 180 capsules, two per serving. That is 90 servings and 22.2p a day. The 90 capsule pouch: 9.99 pounds, 90 capsules, two per serving, 45 servings, 22.2p a day. Identical, which means the larger tub is about not reordering rather than a discount.

Why Amazon's price per count is not a shortcut

Amazon shows a price per count and count means capsule. On a two capsule serving that figure is exactly half the real daily cost, and on a four capsule serving it is a quarter.

That makes it useless for comparing across products with different serving sizes, which is most of the magnesium category. A product showing 5p per count and requiring four capsules a serving costs 20p a day, and one showing 11p per count at two capsules costs 22p. Those look four times apart and are within 10 percent of each other.

Cost against active content

Cost per day only means something alongside what a serving actually delivers. A cheaper daily cost at a lower elemental figure is not better value, it is a smaller purchase.

The comparison that resolves it is cost per 100mg of elemental magnesium. Futuro Labs Magnesium Glycinate delivers 300mg elemental for 22.2p, which is 7.4p per 100mg. A product at 15p a day delivering 100mg elemental is 15p per 100mg, so it is half the daily price and twice the cost for what it contains.

What a season and a year come to

At 22p a day, a 34 week season is about 53 pounds and a full year is about 81 pounds. Weekly that is 1.55 pounds, which is less than a single pint in most clubhouses.

Adding Futuro Labs Omega 3 Fish Oil at 17p takes the daily figure to 39p, or about 142 pounds a year. The full range of four, adding Futuro Labs Marine Collagen at 28p and Futuro Labs Lion's Mane at 13p, comes to 80p a day, which is about 292 pounds a year. That last figure is a real amount of money and it is worth seeing before committing to four products rather than one.

Where the money actually gets wasted

Not on the products with a stated dose at a fair price. It gets wasted on products where the front of the pack shows a large compound weight, the elemental figure is absent, and the serving turns out to be three or four capsules.

Those products are usually cheaper per tub, look better value on a shelf, and cost more per day for less magnesium in a less absorbable form. That combination is common enough that running the arithmetic is worth the ninety seconds every time.

Subscriptions and multipacks

Amazon subscribe and save style discounts change the arithmetic slightly and are worth running rather than assuming. A five percent saving on a 19.99 pound tub takes 22.2p a day to 21.1p, which across a season is about two and a half pounds.

Multipacks are the more common trap. Two tubs at a small discount look like value and only are if the product gets taken for 180 days, which on the adherence evidence is not the default. A player who stops in November has bought 180 days of something they used for ninety.

Futuro Labs Magnesium Glycinate is 22p a day on both the 180 and 90 capsule packs, so the sensible first purchase is whichever size matches how confident a player is that they will keep taking it. The 90 capsule pouch at 9.99 pounds is a 45 day trial of the habit as much as of the product.

Comparing across the whole range

The same arithmetic run on all four products gives the numbers this site quotes everywhere, and it is worth showing the working once.

Futuro Labs Magnesium Glycinate: 19.99 pounds, 180 capsules, two per serving, 90 servings, 22p. Futuro Labs Omega 3 Fish Oil: 14.99 pounds, 90 softgels, one per serving, 90 servings, 17p. Futuro Labs Marine Collagen: 16.99 pounds, 120 capsules, two per serving, 60 servings, 28p. Futuro Labs Lion's Mane: 15.49 pounds, 120 capsules, one per serving, 120 servings, 13p.

Collagen is the dearest per day and lion's mane the cheapest, which is the reverse of what the claim positions would suggest, since collagen carries none of its own and lion's mane carries nothing at all. Price and evidence are not correlated in this category and that is worth seeing plainly.

Where to go next

• What to look for in a magnesium supplementThe full label method, with two products compared step by step.
• Best magnesium for club rugby playersWhat this looks like against the rest of a club rugby budget.
• How to read a supplement labelThe same arithmetic applied across all four products.

Questions players ask

Sources

• EFSA register of nutrition and health claims
• National Diet and Nutrition Survey, gov.uk
• Food supplements guidance, gov.uk