We don’t know much about the health effects of synthetic cannabinoids. Many synthetic cannabinoids have only recently been developed. They have not been approved for human consumption and there is there is very limited information available regarding their short and long-term effects.

The majority of information based on medical research around synthetic cannabinoids has focused on JWH products – in particular JWH-018 and JWH-073. Not all synthetic cannabinoid products are based on JWH compounds.

JWH compounds are believed to be active at doses around 2-4mgs when smoked. The effect they have on the consumer tends to be similar to the high people report from cannabis, but with a longer time before onset and shorter duration.

Common reported effects of synthetic cannabinoids include:

• a similar effect to smoking cannabis
• disconnection from thoughts, feelings, memories and sense of identity (dissociative state)
• fast and irregular heartbeat
• relaxation
• euphoria
• rapid pulse rate
• racing thoughts
• delayed reaction time
• dry mouth
• lowering of inhibitions
• dizziness
• agitation
• anxiety
• paranoia

Health professionals and synthetic cannabis consumers have reported that the toxic effects of synthetic cannabinoids can be significant. Adverse effects reported in New Zealand include:

• rapid heart rate 
• hypertension
• tachypnea (rapid breathing)
• abdominal pain
• nausea
• vomiting
• chest pain
• heart palpitations
• severe paranoia, especially around fear of dying
• hallucinations
• racing thoughts
• seizures
• tremors
• hallucinations
• psychosis, sometimes lasting for several days

Toxic symptoms generally last no longer than 3-4 hours, with no remaining adverse effects in many cases.  However there is increasing concern about serious acute and long-term toxicities and long-lasting psychosis in some consumers.  People with pre-existing mental health conditions appear to be particularly negatively affected by synthetic cannabinoids.

The National Poisons Centre reports that the increased availability of synthetic cannabinoids has resulted in more calls from doctors and ambulance officers reporting breathing problems, paranoia and recurring psychotic episodes. New Zealand doctors have reported concerns over the increase in clients in their emergency departments suffering adverse effects.

The inventor of synthetic cannabinoids, Emeritus Professor John Huffman, has publically declared his concern over their use, saying they can lead to serious psychological problems which may be irreversible.