Scientists have made their own version of marijuana and the high lasts 2 days!

THC is the active component in the Cannabis plant that makes people high. In 1949, scientists were hired to examine the components of THC and explain how they work. In doing so, they invented their own type of synthetic THC called Dimethylheprylpyran or DMHD.

DMHD is made exactly the same as THC with the exception of one double bond that is in a different position. This double bond positioning changes the effects in the drug drastically. While the psychological effects may be diminished, the sedative effects are far more extreme. DMHD also shows an increase in it's pain relief side effects, as well as, being a potent anti-convulsant which would be helpful for someone who has seizures.

The drug does come with some negative side effects. The high when consuming DMHD could last anywhere from two to three days. Due to the extreme fatigue, it has been reported that a person may not even be able to stand up, let alone function during the time of being high. During early testing, even the United States Chemical Weapons Program did extensive research because it was considered a non-lethal incapacitating agent.

(Source)