German researchers are hoping to get government backing for a new study that would see the recruitment of 25,000 recreational marijuana smokers.

The Research Initiative on Cannabis Consumption are seeking government approval to analyse the cannabis users in order to understand the effects of the drug after several years of use.

The group handed over an updated application to the Federal Institute for Drugs and Medical Devices (BfArM) earlier in April.

Their application is aimed at conducting a "Scientific Study on Cannabis Sequences for Mentally Healthy Adult Consumers" they say.

Germany legalised marijuana for medicinal purposes earlier in 2017 with new powers given to doctors to prescribe the drug to seriously ill patients at their discretion.

This, researchers say, paves the way for a new study analysing the longer-term effects of the drug.

Cannabis for recreational use is still illegal, but that hasn't stopped 2,000 people already signing up for the study, say the researchers.

The group announced plans to begin the study in November 2016 saying it wanted to analyse the mental effects on those addicted to the drug.

"In Germany several million people regularly get high on cannabis," wrote lawyer and chief executive of the project Marko Dörre in a statement released after the plans were submitted.

"It is time that science becomes more engaged with recreational use."

Marijuana
German researchers are hunting for 25,000 cannabis smokers for a new study. Reuters/John Vizcaino

As part of the study, those selected would be permitted to pick up 30 grams of pharmaceutical cannabis, usually reserved for medical patients, on a monthly basis.

Researchers are prohibiting anyone under 18, first-time marijuana smokers, as well as candidates with high-risk of addiction or psychiatric problems, from taking part in the study.

Before the new act on the Amendment of Narcotics Regulations passed earlier this year, only around 1,000 people with serious medical conditions were permitted to use cannabis.

"With the law implemented in March changing controlled substance regulations, the German parliament took on a new risk assessment of cannabis," said Dörre.

"The new assessment will also benefit science."

The BfArM declined to comment to Tagesspiegel as to whether it had in fact received the application or the chances of it being approved.