The government has slightly revised rules on the sale and use of cannabis as a “controlled herb” amid concern about recreational drug use.

Thailand in June became the first country in Asia to decriminalise the use of cannabis, but designated the plant as a controlled herb and banned sales of all parts of the plant to people under age 20 and women who are pregnant or breastfeeding.

Cannabis liberalisation was a policy of the Bhumjaithai Party led by Anutin Charnvirakul, a deputy prime minister and minister of public health. However, recreational use of marijuana has skyrocketed in just a few months.

Mr Anutin has insisted that recreational use was never his goal, and said that tourists who come to Thailand to get high should think again.

The revised rules announced late Friday by the Ministry of Public Health say that only cannabis buds — the flowers that contain the main concentrations of cannabinoid drugs — will be considered a controlled herb. Their sale will be banned to people under 20 and to pregnant or breastfeeding women.

Licensed businesses must also report to the government the amount of controlled-herb stocks they hold and details of the sourcing and uses. Businesses are required to inform the government each time they export controlled herbs.

It is not clear yet how this might affect the many dispensaries that have opened, especially in Bangkok and some tourist spots, and are selling weed and even rolled joints openly to customers.

The Move Forward Party on Thursday called for the suspension of the ministerial announcement removing cannabis from the list of narcotic drugs, pending a more thorough law on cannabis control.