More than 150,000 people registered to cultivate cannabis with the Food and Drug Administration (FDA) on Thursday as the decriminalisation of the plant took effect.
Dr Paisarn said that apart from the online registration requirement, growers will not have to seek permission to cultivate plants.
On Thursday morning, the app was downloaded more than 50,000 times and more than 150,000 completed the registration process, he said.
The FDA is issuing electronic certificates for people who have successfully registered, he said, noting that if the certificate is abused, it will be revoked.
After registering, people can grow and use cannabis or hemp for medical and commercial purposes, the FDA secretary-general said.
However, people must seek permission under the relevant laws before mixing extracts containing more than 0.2% of tetrahydrocannabinol (THC), cannabis' active ingredient, in their products, he said.
Products with THC content over 0.2% are still considered narcotics, he said.
The de-listing of hemp and cannabis from the government's Category 5 narcotics list took effect on Thursday following the publication of a Ministry of Public Health announcement in the Royal Gazette.
Consequently, the production, import, export, distribution, consumption and possession of cannabis and hemp are formally legalised.
Cannabis oil extracts containing more than 0.2% of the THC are still considered a Category 5 substance, regulated by narcotics control and suppression laws.
Aside from the website, Public Health Minister Anutin Charnvirakul on Thursday said people can also register their plants with agencies assigned by the FDA, such as provincial public health offices.
Regarding the cannabis and hemp bill that passed its first reading in parliament on Wednesday, Mr Anutin said a House panel has been set up to scrutinise the bill, a process that will take about 30 days before the next reading begins.
He said the government plans to push the passage of the bill before the end of the current House session.
Responding to criticism over the de-listing benefiting major business groups instead of smaller ones, Mr Anutin said this is a matter of competition.
He said producers must ensure their goods meet quality standards to boost income.
Mr Anutin on Thursday chaired the first meeting of a committee tasked with integrating the new policy at Government House.
The meeting was attended by Justice Minister Somsak Thepsutin and members of other related agencies.
Mr Anutin said the committee was set up at the behest of the prime minister to ensure the use of cannabis and hemp is in line with the government's policy.
He said that the government has acknowledged concerns regarding abuse of the plant following its de-listing, insisting that the government has not approved the abuse or misuse of cannabis.
The committee will lay down measures to control use and set standards for products, he said, adding it will communicate with the public and educate them on the matter.
The committee will be disbanded after the bill on cannabis and hemp is enacted into law, Mr Anutin said.
Thawatchai Chaiwat, deputy director-general of the Corrections Department, said a total of 3,071 inmates serving time for cannabis offences were released from prisons nationwide on Thursday when the delisting took effect.
Pol Gen Roy Ingkapairote, deputy national police chief, said previously that police will not arrest anyone who smokes cannabis at home. But if they smoke it in public areas and cause a public disturbance, they can face charges, he said.