Legal highs can carry serious health risks. The chemicals they contain have in most cases never been used before in drugs for human consumption. 

This means they haven't been tested to show they are safe. Users can never be certain what they are taking and what the effects might be.

Other risks:

  • You increase the risk to yourself if you combine alcohol with any legal or illegal drug. 
  • Legal highs can reduce your inhibitions, so you do things you wouldn't normally do. They can cause paranoia, coma, seizures and, in rare cases, death. 
  • Because the chemical ingredients in a branded product can be changed without you knowing, the risks are unpredictable. 
  • Even drugs that look similar or have similar names may be of varying strengths and have different effects. 

When to get medical help

Most problems with short-term use of legal highs will settle after you stop taking them. However, the negative effects of some legal highs can take a few days to wear off completely, just like the comedown from stimulants such as cocaine or amphetamines.

If you think you're having a serious negative reaction soon after taking a legal high, or you experience problems that do not settle with a little time out, fluids and fresh air, get medical help straight away by going to the accident and emergency (A&E) department of your nearest hospital.

If you're worried about continuing health problems after you've stopped taking the drugs, visit your GP. But if you think further advice would be helpful before deciding whether or not to visit your GP, call the FRANK drugs helpline on 0300 123 6600, or 

NHS 111.