Mephedrone (also known as meph, MCAT, meow meow) is a drug sometimes used during chemsex because it can increase energy, confidence, pleasure, and horniness.  

The effects, risks, and how long it lasts can vary depending on how you take it. Some people use mephedrone occasionally and feel in control of their use. For others, it can quickly become difficult to manage, especially because it can create strong urges to redose and keep going. 

This guide is about reducing harm, staying safer, and knowing when to get help. 


What does mephedrone feel like? 

The effects can change depending on the dose, how you take it, your body size, tolerance, whether you’ve eaten, and whether you’ve mixed it with other drugs or alcohol. 

People may experience good and bad side-effects of mephedrone: 

  • Feeling euphoric or very happy
  • Increased confidence
  • Increased horniness and pleasure
  • Feeling alert or energised
  • Feeling chatty or connected
  • Reduced inhibitions
  • Jaw clenching or teeth grinding
  • Sweating or overheating
  • Racing heart
  • Anxiety or paranoia
  • Trouble sleeping 

Higher doses of mephedrone can increase the risk of panic, chest pain, overheating, collapse, seizures, psychosis, or overdose. 


Step 1: know what you’re taking 

Mephedrone usually comes as a white/off-white powder or crystals, but it’s appearance doesn’t guarantee what it is. Drugs can be mixed with other substances or vary in strength. 

This means one person’s “normal dose” may be too much for someone else. 

To stay safer, think about: 

  • Never assume it is pure mephedrone
  • Never assume someone else’s dose is right for you
  • Start with a lower dose than usual if it’s a new batch
  • Get it from someone you trust of you can 

Step 2: choose how to take it more safely 

People may use mephedrone in different ways, including snorting, swallowing, booty bumping (rectal use), or slamming (injecting). Each method carries different risks. 

To stay safer, think about: 

  • Starting on a lower dose and wait before taking more
  • Using your own equipment only
  • Avoiding sharing straws, notes, syringes, needles, spoons, or water
  • If injecting, use sterile needles and clean preparation equipment every time
  • Rotate injection sites and stop if there is pain or swelling 

Step 3: pace yourself 

Mephedrone can make you want to keep taking more. Repeated dosing can increase anxiety, overheating, dehydration, and physically and mentally crashing. 

To stay safer, think about: 

  • Waiting before taking more and seeing how you feel first
  • Deciding in advance how much you plan to use
  • Splitting amounts beforehand rather than using from one large bag
  • Setting alarms and checking in with a friend
  • Taking breaks from sex and stimulation 

Step 4: don’t mix mephedrone with certain drugs 

Mixing mephedrone with other can make it harder to judge how high you are. 

To stay safer, be careful mixing mephedrone with: 

  • Methamphetamine or cocaine - it can cause strain on your heart and on your mental health
  • MDMA - it increases overheating and can impact your mood
  • GHB/GBL - it can mask the effects and increase the risk of overdose
  • Erectile dysfunction meds - if you already feel chest strain or racing heart
  • Alcohol - it can cause dehydration, poor judgement, and harder recovery 

If you take prescribed medication, especially antidepressants or heart medication, mixing can also carry risks. 


Step 5: set boundaries before using mephedrone 

When using mephedrone, sessions can last much longer than planned and you might go beyond your limits when you’re high. That’s why going in with a plan and setting personal boundaries can help. 

To stay safer, think about: 

  • Who are you meeting?
  • What sex are you comfortable having?
  • What are your hard limits?
  • Are condoms, PrEP or DoxyPEP part of your plan?
  • Who can you contact if something goes wrong?
  • What time do you want to leave or stop? 

It can help to share boundaries with any partners before taking it. Looking out for each other is a great way to stay safer. 


Step 6: look after yourself while using mephedrone 

It might seem simple, but small things can make a big difference. 

To stay safer, think about: 

  • Sipping water regularly, especially if hot or active
  • Taking cooling breaks if overheating
  • Eating something beforehand if you can
  • Using lube to reduce friction and injury during longer sessions
  • Charging your phone
  • Avoiding using alone if possible
  • Staying around people you trust 

What if someone takes too much mephedrone? 

Taking too much mephedrone can lead to an emergency situation. 

Look out for: 

  • Chest pain
  • Trouble breathing
  • Seizure
  • Collapse or unresponsiveness
  • Very high temperature
  • Severe agitation or panic
  • Paranoia or psychosis
  • Irregular heartbeat
  • Blue lips or skin 

If you spot any of this you should: 

  • Call 999 immediately
  • Stay with them
  • Move them somewhere cooler if overheating
  • Keep them calm if conscious
  • Put them in the recovery position if unconscious and breathing [LINK]
  • Tell paramedics what was taken if you know
  • Do not give more drugs or alcohol 

Call 999 in an emergency. Ambulance staff are there to help keep people safe without judgement. 


Finding support 

If chemsex is starting to affect your wellbeing, relationships, sex life, finances or mental health, support is available. 

The Chemsex Support Hub offers non-judgemental information and help for LGBTQ+ people around chemsex, sexual health and wellbeing. [LINK]