The sale of legal cannabis oil used for treating ailments has doubled in 12 months.

And because high street chain Holland & Barrett has been selling the product for a month, sales of the medicinal oil have accelerated further.

The Cannabis Trades Association UK says the number of cannabidiol users has increased from 125,000 a year ago to 250,000 today.

Unlike its illegal counterparts such as hashish, marijuana and skunk, cannabidiol (CBD) does not produce a high as it contains less than 0.2% THC (­tetra­­­hydro­­cannabinol) which is the chemical that gets the user stoned.

Unlike illegal skunk cannabis, legal cannabis oil will not get you high.

'CBD+Oil', produced by Dutch firm Jacob Hooy has been selling at an additional 37% since Holland & Barrett started stocking the product.

According to the Mirror , Holland & Barrett will be stocking four additional cannabis oil products next month.

CBD oil is used to ease the symptoms of multiple ­sclerosis, joint pain, anxiety and depression, along with a range of other conditions.

It is made by pressing hemp leaves and flowers.

A Holland & Barrett spokesperson said: “We have been surprised at the success and popularity of CBD oil since its launch.

“We are constantly looking to bring new and innovative ­products to market that help our customers.

“It is great to see in this instance that we can help with the demand.”

But the chain’s website has mixed reviews of the oil, with comments ranging from “excellent for many ailments – liquid gold” to “I’m not noticing anything”.

Jacob Hooy CBD+Oil costs £19.99 for a 10ml bottle, with users putting drops under the tongue.