Immediate effects
The effects of hallucinogens begin within half an hour of taking the drug, are strongest in three to five hours, and last for up to 12 hours.

They can include:

• seeing, hearing, touching or smelling things in a distorted way, or that don’t exist (you usually know that what you are sensing is not real)
• intense sensory experiences (eg colours become very bright, sounds become sharper)
• mixing of the senses (eg you ‘hear’ colours or ‘see’ sounds)
• changed sense of time (eg minutes can seem as slow as hours, or you can ‘re-live’ something that happened a long time ago)
• space becomes distorted
• strange bodily sensations (eg as though you are floating or being pulled down by gravity, or that you are becoming part of another object)
• changed and intense thoughts
• emotional swings (eg change from intense happiness to deep sadness).

Effects on your body may include things like:

• your muscles twitch
• you feel weak
• you feel numb
• your pupils get bigger
• you shake
• you feel sick or vomit
• your heart beats faster
• your blood pressure rises
• you breathe faster and deeper than normal
• your coordination is poor.

‘Bad trips’
Sometimes the effects of hallucinogens are mostly negative. This is called a ‘bad trip’ and it is common among first time users. Effects of a bad trip can include:

• extreme anxiety or fear
• frightening hallucinations (eg spiders crawling on the skin)
• panic, leading to taking risks (eg running across a busy street)
• feelings of ‘losing control’ or ‘going mad’
• paranoia (feeling that other people want to harm you)
• suicide or violence (rare).

If someone you know is having a ‘bad trip’, they need to be reassured and comforted until the effects of the drug wear off. This can take many hours and may not disappear altogether for some days.