Marijuana is still a drug under the Thai drugs law and its use for medical purposes requires strict legal control measures, a senior narcotics official said.
Despite cabinet approval for a legislative bill permitting research into the effects of medicinal cannabis on humans, marijuana is still categorised as a Class 5 narcotic under the 1979 Narcotic Drugs Act, said Sirinya Sitdhichai, secretary-general of the Office of the Narcotics Control Board (ONCB).
According to the Narcotics Act, the planting of the marijuana plant is allowed for medical purposes and use of the plant does not extend to medical research involving humans.
While the ONCB has supported the use of cannabis for medical purposes, its use for other purposes, such as recreational use is still illegal, Mr Sirinya said.
The cabinet on Tuesday approved the draft legislation drawn up by a panel led by the ONCB.
The agency works closely with the Government Pharmaceutical Organisation (GPO).
The draft legislation will go to the National Legislative Assembly (NLA) who will pass it into law, said Sophon Mekthon, head of the committee that drafted the law.
Dr Sophon, who is also the chairman of the GPO board, said it was still not known when the legislative process would be completed.
However, if the draft is endorsed by the NLA, the law would come into effect within 180 days of it being published in the Royal Gazette.
The main thrust of the draft code is to allow research into the effects of cannabis on humans for medical benefits.
It does not allow for commercial product or recreational use. The ONCB will decide where the research trial will be conducted.
Dr Sophon said a possible location is the GPO compound on Rama VI Road covering about 1,000 square metres.
A resolution made by the cabinet on Tuesday also authorises the Public Health Minister and committee working on extracting substances from the marijuana plant for medical use to control production, import, export, and possession for research purposes.
The cabinet also authorised the ONCB to designate strictly controlled environments for planting, production, and extraction of the marijuana plant for the trial.
Viroj Sumyai, president of the International Narcotics Control Board (INCB), said the United Nations does not prohibit the use of substances extracted from marijuana for medical purposes.
"Commercial planting and production is prohibited except when it is done by the state for research and medical purposes under strict control," Mr Viroj said.