# Sleep

In Britain the biggest question around sleep supplements is a legal one. "Why is melatonin illegal in the UK" and "buy melatonin uk" are each searched more than twice as often as "sleep supplements" itself, and the NHS states the position in six words: "Melatonin is available on prescription only."

Magnesium carries the buying searches instead. "Magnesium for sleep" is the largest term in this goal by a distance, and "magnesium glycinate for sleep" the largest of the salt-specific ones. Where a pack prints a capsule or tablet count, the ranking uses price per unit; where it does not, as on a tub of powder, only the pack price survives. Neither ranking normalises the dose, so the milligrams on the label are yours to match, and whether any of it suits you is a question for a GP or pharmacist.

Best and median price per ingredient, updated 18 October 2026

| Ingredient | Best price | Product | Median price | Shops | Products |
| --- | --- | --- | --- | --- | --- |
| [Magnesium](https://supplementscanner.co.uk/category/magnesium) | £0.04 /capsule | [New Era No.8 Mag Phos - 240 Tablets](https://supplementscanner.co.uk/p/new-era-new-era-no8-mag-phos-240-tablets-144775) (Vitamin Planet) | – | 12 | 92 |
| [L-Theanine](https://supplementscanner.co.uk/category/l-theanine) | £0.14 /capsule | [Theanine 90 capsules](https://supplementscanner.co.uk/p/predator-nutrition-theanine-90-capsules-127785) (Predator Nutrition) | – | 1 | 1 |
| [Apigenin](https://supplementscanner.co.uk/category/apigenin) | £0.06 /capsule | [The Health Project Apigenin 200mg \| Antioxidant & Wellness Support](https://supplementscanner.co.uk/p/the-health-project-the-health-project-apigenin-200mg-antioxidant-wellness-support-133618) (Discount Supplements) | – | 2 | 2 |
| [Ashwagandha](https://supplementscanner.co.uk/category/ashwagandha) | £0.11 /capsule | [Warrior Ashwagandha - 90 Capsules](https://supplementscanner.co.uk/p/warrior-warrior-ashwagandha-90-capsules-133113) (Bodybuilding Warehouse) | – | 10 | 44 |
| [Glycine](https://supplementscanner.co.uk/search?q=glycine) | £4.99 total price | [Glycine](https://supplementscanner.co.uk/p/bulk-glycine-125439) (Bulk) | – | 6 | 13 |
| [Sleep formulas](https://supplementscanner.co.uk/category/sleep-support) | £0.08 /capsule | [Night Time Formula – 120 capsules / [Multibuy 1]](https://supplementscanner.co.uk/p/simply-supplements-night-time-formula-120-capsules-multibuy-1-132073) (Simply Supplements) | – | 8 | 44 |

## Glycinate, citrate, oxide: the two numbers on a magnesium pack

Two numbers decide a [magnesium](https://supplementscanner.co.uk/category/magnesium) comparison, and only one of them is on the front. The front carries the salt: oxide, citrate, malate, glycinate or bisglycinate, taurate, L-threonate. The second number, elemental magnesium in milligrams, sits in the nutrition table, and it moves a long way between salts at the same capsule weight. That arithmetic is worked through in buying magnesium.

Magnesium spray, magnesium cream and magnesium drinks are all searched in Britain too. None of them states a capsule count, so none of them reaches a per-unit price.

## Where melatonin sits, and what sits beside it

[Melatonin and sleep](https://supplementscanner.co.uk/category/sleep-support) is a single category across every market, holding single-ingredient melatonin tablets and combination night formulas alike, ranked per tablet. Under "sleep supplements" the British results that rank are retailer listings of the second kind: valerian, passionflower, hops, lemon balm, chamomile, often with vitamin B6 beside them.

The label decides whether that ranking means anything. Some packs give one line per plant with its own milligram figure; others print a single "herbal blend" line and no figures at all. A pack of the second kind cannot be set against a pack of the first, wherever it lands in the order. Which other words on a pack fix nothing at all is set out in reading a supplement label.

## The two labels that leave the arithmetic to you

Two of the six lanes print a percentage where a dose was expected. [Apigenin](https://supplementscanner.co.uk/category/apigenin) arrives either as apigenin in milligrams or as a chamomile extract standardised to a percentage of apigenin; in the second case the milligram figure only exists after a multiplication.

[Ashwagandha](https://supplementscanner.co.uk/category/ashwagandha) splits the same way, between milled root and an extract carrying a ratio such as 10:1 or a stated percentage of withanolides. KSM-66 and Sensoril are the extract names most often printed. Root and extract are not the same capsule, and the ingredient turns up again on [menopause](https://supplementscanner.co.uk/goal/menopause).

## L-theanine prints its number; glycine is sold by the tub

[L-theanine](https://supplementscanner.co.uk/category/l-theanine) asks nothing of the reader: milligrams per capsule, printed as such, with 100, 200 and 400 mg formats on sale. Suntheanine is a brand of the same molecule rather than a different strength, and where green tea extract shares the panel only the L-theanine line counts. The same capsules turn up on [energy and focus](https://supplementscanner.co.uk/goal/energy-focus).

Glycine has no category of its own, so the comparison stops at the pack. A name match brings back powders dosed in grams per scoop alongside capsules dosed in milligrams, and the servings figure on the packaging is what turns that pack price into anything finer.

## The long tail of British sleep search

Beyond the head terms sit the shop and format names: "sleep supplements boots", "sleep supplements natural", "sleep supplements ashwagandha", "melatonin gummies uk". Adding a shop to a query narrows where to buy and never what the label says, and the melatonin variants arrive back at the prescription answer. Shops also stay separate: nothing joins two shops to a single product record, so a ranking sets one shop's pack against another shop's pack rather than one product's prices against each other.

## Sources

- [NHS: About melatonin](https://www.nhs.uk/medicines/melatonin/about-melatonin/)
- [NHS: Insomnia](https://www.nhs.uk/conditions/insomnia/)

## Frequently asked questions

### Is melatonin legal in the UK?

Melatonin is a prescription-only medicine in the UK. Searches for buying it land on the NHS, on pharmacies and on online doctors rather than on retailer listings, and the UK results for "sleep supplements" are herbal night formulas. The NHS page on melatonin is the source.

### What can I take instead of melatonin in the UK?

A price list cannot answer that; a GP or pharmacist can, and the NHS page on insomnia is the other starting point. What the recorded searches put ahead of everything else is magnesium. The shops also sell L-theanine, apigenin, ashwagandha and glycine on their own, alongside night formulas built on valerian, passionflower, hops, lemon balm and chamomile.

### Does NHS recommend magnesium for sleep?

That question belongs to the NHS, not to a shopping comparison, and no recommendation is offered on either side of it. What a comparison can tell you is which figure makes two magnesium packs comparable: the elemental magnesium in milligrams, printed below the salt in the nutrition table.

### What are the best supplements for sleep?

No ranking of that kind comes out of comparing prices. Magnesium is the name British search asks about most around sleep, and glycinate, spelled either glycinate or bisglycinate, is the salt most often named in those queries. Whether two packs of it can be compared per capsule depends on the elemental figure each one prints.

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Source: Supplementscanner, https://supplementscanner.co.uk/goal/sleep (live prices per product)

Information for comparison, not medical advice. Ingredients are chosen based on what people often search for, not as a treatment.