In a sentence? You don’t know what’s in the product.
Even when the substance is known, it’s usually not been used for human consumption before and any risks or effects are unknown. There has only been very limited research into the short and long term effects of ‘legal highs’. However, it is clear that they pose a severe risk to your health and well being.
There have been countless reports of legal highs causing: dizziness, drowsiness, paranoia, psychosis, hallucinations, nausea, overheating, coma and seizures. Many new psychoactive substances have been the cause of hospital visits and in serious cases even death.