The Best Supplements for Stress in the UK, Honestly Ranked

Stress supplements are the most over-promised corner of the wellness shelf. Nothing in a jar is going to fix an unmanageable workload, and any brand implying otherwise is selling you a story. What a good formula can do is support the machinery your body uses to cope, and in the UK, only a handful of ingredients are legally allowed to say even that.

So here is a ranked list, written by a brand that makes one of the products on it. Ours is first, and we will show our working. Everything else is here because it is genuinely good at something, and we say where it beats us.

Formulations and prices change. Every statement about another brand comes from their public product pages at the time of writing, check the current label. The only figures we can permanently stand behind are our own, because we publish the batch tests.

How we ranked them

1. Is the active dose disclosed? Individual amounts, not a proprietary "calm blend".
2. Is the ashwagandha standardised? Extract ratio or withanolide percentage, or it is just root powder.
3. Is anything allowed to make a claim? Magnesium and vitamin B6 contribute to normal psychological function. Adaptogens, in UK law, cannot claim anything.
4. Can you see the batch tests without emailing anyone?

1. Grass & Co. RELAX, Maitake, Ashwagandha & Magnesium

Best overall, and the one we make.

RELAX pairs 500mg organic Maitake fruiting-body extract with ashwagandha, two traditional adaptogens, then does the thing most calm supplements skip: adds the nutrients that are actually permitted to carry a claim. Magnesium and vitamin B6 contribute to normal psychological function, normal nervous system function, and the reduction of tiredness and fatigue. That is not marketing language; it is the regulator's.

Maitake is the least famous of the functional mushrooms and one of the more interesting ones, we wrote it up in Maitake for stress.

Pros

• 100% organic fruiting body extract. No mycelium-on-grain.
• Certificates of analysis published for every batch.
• Authorised nutrient claims on the pack, so the label is defensible.
• Non-sedating, it is a daytime formula, unlike most of the category.
• Vegan Society registered; sourcing verified by Provenance. Built as a blend for the reasons in the & Co. effect.

Cons

• Contains ashwagandha, so it is not for you if you are pregnant, breastfeeding, on thyroid medication or have a thyroid condition without speaking to your GP. See safety and interactions.
• Two capsules a day.
• Works by accumulation over weeks, not on the afternoon you take it.
• Not a sleep product. That is DREAM.

See RELAX capsules

2. Grass & Co. Liquid RELAX

Best for people who will never remember a capsule.

1,000mg Reishi with ashwagandha and chamomile, plus magnesium and B6, in a sparkling peach can. The honest case for it: adherence. A drink you enjoy at six o'clock gets consumed; a jar in a cupboard does not.

Pros: the alcohol-free evening ritual is the real product; low sugar; portable.

Cons: more expensive per day than capsules; fridge space; lower total active load than a two-capsule serving.

3. KSM-66 ashwagandha (Wild Nutrition, Bulk and others)

Best single-ingredient option.

If you want the most-studied stress botanical and nothing else, buy a standardised KSM-66 extract from a brand that states the withanolide content. Several UK sellers do this well and it is a perfectly rational purchase.

Pros: the strongest research base of any adaptogen; cheap at the commodity end; simple.

Cons: no supporting nutrients and therefore no authorised claim; quality varies wildly between sellers; the same contraindications as ours, with less guidance attached.

4. Pukka Night Time or Relax teas

Best for a calming ritual that costs almost nothing.

Organic herbal tea, chamomile, valerian, oat flower, from a B Corp with two decades of herbal sourcing behind it. If your stress relief is partly the five minutes of making something warm, this is the cheapest reliable version of that, and it stacks with anything else on this list.

Pros: pennies per cup; organic and widely available; the ritual itself does real work; no interactions to worry about for most people.

Cons: herbal infusion doses are low by nature, so do not expect a formulation-strength effect; no authorised claim; valerian is not for everyone.

5. Magnesium glycinate (any reputable UK brand)

Best value, and the one most people underrate.

Unglamorous and frequently the only part of a calm supplement doing measurable work. It carries authorised claims for psychological and nervous system function, and it costs almost nothing.

Pros: cheap; authorised claims; well tolerated in glycinate form.

Cons: no adaptogen, no mushroom, no story; oxide forms are poorly absorbed so the form matters; will not touch a stress problem that is structural.

6. Grass & Co. CALM CBD Oil

Included for completeness, with the legal caveat.

Our CBD range has been on the Holland & Barrett shelf since 2020. UK law does not permit CBD to make any health claim, and the Food Standards Agency advises healthy adults not to exceed 10mg of CBD a day, so we will not tell you what it does. What we will say is that a large number of people use it as part of an evening routine, and that if you buy CBD you should buy it from someone who publishes their certificates. Read what's in your CBD first.

Pros: full third-party testing published; long-standing high-street availability.

Cons: no permitted claims, so you are making your own judgement; 10mg/day FSA advisory; not suitable while pregnant or breastfeeding.

What we would actually tell a friend

Take ours if you want the mushroom and the adaptogen with nutrients that make the label mean something. Buy plain magnesium glycinate if money is tight, it is the highest-value item on this page. Buy the drink if you know yourself well enough to know the capsules will end up unopened.

And take the boring advice seriously. Nothing here competes with a walk, a proper lunch break, and an actual conversation about your workload. If the stress is chronic and physical, see a GP rather than a shelf. Our take on why the cortisol conversation gets oversimplified is in could high cortisol be affecting you.