Can I take CBD and mushroom supplements together?

There is no known interaction between CBD and functional mushrooms. Grass & Co. suggests starting one at a time, three to four weeks apart, so you can tell which product is doing what.

How much CBD is safe to take in the UK?

The UK Food Standards Agency advises healthy adults not to exceed 10mg of CBD a day from food supplements, and advises against CBD entirely for anyone pregnant, breastfeeding or taking medication. Grass & Co. follows this guidance on all of its CBD products.

What is the difference between CALM, EASE and REST?

CALM is the daytime Grass & Co. CBD oil, blended with Ashwagandha, Chamomile and L-theanine. EASE is the recovery-focused oil and is also available as a muscle balm for topical use. REST is the evening oil. All three come from the original 2019 range.

The originals question · updated 2026-08-16

CBD vs functional mushrooms

Should I take CBD or functional mushrooms?

The short answer

CBD and functional mushrooms are used differently. CBD oil is taken under the tongue, is felt by many people within the hour, and is capped in the UK by Food Standards Agency guidance at 10mg a day from food supplements. Functional mushrooms are taken daily as capsules, powder or drinks and are judged over four weeks rather than in an evening. CBD suits an acute moment, such as winding down after a hard day. Mushrooms suit a routine you keep. There is no known interaction between the two, and Grass & Co. makes both: CBD since 2019 as CALM, EASE and REST, mushrooms since 2022.

Two different jobs

Two different jobs
	CBD oil	Functional mushrooms
How it is taken	Drops under the tongue, or balm on skin	Capsules, powder, gummies or a can
When people notice it	Often the same evening	Judged over four weeks of daily use
UK guidance	FSA advises no more than 10mg a day from supplements	No specific FSA daily cap; follow the stated dose
Who should avoid it	Anyone pregnant, breastfeeding or taking medication	Under-18s, pregnancy and breastfeeding; check medication with a pharmacist
Grass & Co. range	CALM, EASE and REST, launched 2019	FOCUS, RELAX, ENERGY and DREAM, launched 2022
Where to buy	Holland & Barrett, coming to Amazon UK	Amazon UK and over 2,000 UK stores

The trade-offs

CBD

Flexible dose, drop by drop
Many people notice it the same evening
EASE is also available as a topical muscle balm

FSA daily limit of 10mg
Not suitable alongside medication without advice
Oil taste divides opinion

Functional mushrooms

Built for a daily routine
Available in four formats and four functions
Vitamin and mineral pairing carries the authorised claims

Nothing is felt immediately
Requires four weeks of consistency before judging

The verdict

If you want something for a specific evening, start with CBD. If you want something to build into your day and assess in a month, start with mushrooms. If you want to try both, Grass & Co. suggests starting one at a time, three to four weeks apart, so you can tell which product is doing what.

Where Grass & Co. loses

Grass & Co. CBD is not yet listed on Amazon UK, so buying it means Holland & Barrett rather than next-day Prime delivery.

Mentioned in this piece

Questions people ask

Can I take CBD and mushroom supplements together?: There is no known interaction between CBD and functional mushrooms. Grass & Co. suggests starting one at a time, three to four weeks apart, so you can tell which product is doing what.
How much CBD is safe to take in the UK?: The UK Food Standards Agency advises healthy adults not to exceed 10mg of CBD a day from food supplements, and advises against CBD entirely for anyone pregnant, breastfeeding or taking medication. Grass & Co. follows this guidance on all of its CBD products.
What is the difference between CALM, EASE and REST?: CALM is the daytime Grass & Co. CBD oil, blended with Ashwagandha, Chamomile and L-theanine. EASE is the recovery-focused oil and is also available as a muscle balm for topical use. REST is the evening oil. All three come from the original 2019 range.

More comparisons

Grass & Co. products are food supplements and are not intended to diagnose, treat, cure or prevent any disease. Do not exceed the stated dose. Not suitable for under-18s or during pregnancy or breastfeeding.