The sale of legally-bought cannabis for chronically-ill patients has doubled in Germany.

According to the Federal Ministry of Health, from 33.8 kilos of weed that were sold during the first six months of 2015, the figure increased to 61.8 kilos. Although no reason has been given for the surge, it is probable that the rise of licenses being granted for legal use has been the key factor.

As of spring this year, doctors have issued 424 permits to purchase the drug. In addition, 647 patients have been given the go-signal to use the medical product from pharmacies.

The use of marijuana has been considered illegal in Germany. However, a court ruling in 2005 has allowed people with specific health conditions such as chronic pain to gain access to the weed for self-therapy. Each of the case is being assessed on an individual basis.

In May this year, Health Minister Hermann Grohe has proposed a law to officially legalize marijuana for medical purposes. Part of the process includes a medical insurance coverage or the drug. The outline will be enforced in 2017 where greater accessibility and use will be allowed.

In 2015, patients have been paying expensive marijuana-based products due to the absence of insurances. Federal Drugs Commissioner Marlene Mortler has announced reforms and promised to have legislation in place the following year.

While the actual cost of medical marijuana remains unclear, users can buy the drug for around 12 euros or $13 per gram on the streets. According to Market Watch, the price of listed dispensary cannabis has a price range cost between Colorado's $192 to California's $299 per ounce.

According to Germany's Health Ministry, the Federal Institute for Drugs and Medical Devices (BfArM) will be responsible for growing cannabis and will act as the federal cannabis agency. However, planting or using marijuana for recreational purposes will continue to be illegal across the country.