What are the most commonly used drugs?
When people ask what are the most commonly used drugs in Ireland, they’re usually looking for straightforward information, not scare stories. This guide covers 10 commonly used drugs people may encounter in Ireland, what they are, and why they can be hard to stop using once they’ve become part of someone’s routine.
1. Heroin
Heroin is an opioid made from morphine. It can create a fast sense of relief or detachment by activating opioid receptors in the brain. That “switching off” feeling can become something people start relying on, and withdrawal symptoms can make stopping feel overwhelming without support.
What it looks like: white to brown powder, sometimes sticky or tar-like (less common).
How it affects you: warmth, heavy drowsiness, slowed breathing, nausea, constipation.
How long it can be detectable: often 1–3 days in urine, longer in hair (varies by test and use).
2. Cannabis
Cannabis comes from the cannabis plant, with THC as the main psychoactive ingredient. Some people find it helps them relax, but regular use can start to feel necessary for sleep, appetite, or stress, which is often where psychological dependence builds.
What it looks like: dried herbal cannabis, resin (hash), oils or concentrates.
How it affects you: slowed reaction time, altered perception, increased appetite, anxiety in some people.
How long it can be detectable: from a few days to several weeks in urine, especially with frequent use.
3. Cocaine
Cocaine is a stimulant that increases dopamine, which is why it can feel energising and confidence-boosting. The effects tend to wear off quickly, and that drop can drive cravings and repeated use, especially in social situations or when alcohol is involved.
What it looks like: white to off-white powder, often mixed with other substances.
How it affects you: alertness, fast heart rate, reduced appetite, restlessness, sleep disruption.
How long it can be detectable: commonly 2–4 days in urine (sometimes longer with heavier use).
4. Crack Cocaine
Crack is a form of cocaine that’s usually smoked, which means it reaches the brain very quickly. That rapid “hit” can make it more reinforcing, and some people find themselves re-dosing repeatedly because the effect fades fast.
What it looks like: small crystals or “rocks”.
How it affects you: intense stimulation, agitation as it wears off, sleep loss, appetite suppression.
How long it can be detectable: often 2–4 days in urine.
5. Amphetamine (often called “speed”)
Amphetamines are stimulants that raise dopamine and noradrenaline. They can make someone feel driven and switched on, but regular use can lead to tolerance, disrupted sleep, and a low mood “crash” that pulls people back into using.
What it looks like: powder or paste, sometimes tablets (varies).
How it affects you: energy, talkativeness, sweating, jaw tension, anxiety, insomnia.
How long it can be detectable: commonly 1–3 days in urine.
6. Mephedrone (4-MMC)
Mephedrone is a synthetic stimulant (a cathinone). In conversations about mephedrone Ireland, people often describe a rush of energy and sociability, followed by a noticeable dip. That up-and-down pattern can lead to frequent re-dosing and stronger cravings over time.
What it looks like: white/off-white crystals or powder, sometimes capsules.
How it affects you: euphoria, increased heart rate, agitation, anxiety as it wears off.
How long it can be detectable: often 1–3 days in urine (testing varies).
7. Ecstasy (MDMA)
MDMA is commonly taken for feelings of connection, energy, and wellbeing. It strongly affects serotonin, which can leave people feeling emotionally flat or low afterwards, especially with repeated use, higher doses, or little sleep.
What it looks like: tablets (often with logos), capsules, or crystals.
How it affects you: energy, emotional openness, jaw clenching, overheating risk in warm settings.
How long it can be detectable: commonly 1–3 days in urine (sometimes longer).
8. LSD
LSD is a powerful psychedelic that changes perception and can intensify emotions. It doesn’t usually cause physical dependence, but it can still become risky if someone uses it to escape distress, or if trips start to feel unpredictable or destabilising.
What it looks like: blotter paper tabs, tiny tablets (“microdots”), or liquid.
How it affects you: visual distortions, altered time, heightened emotions, possible panic reactions.
How long it can be detectable: often 1–3 days in urine (varies by test).
9. Magic mushrooms (psilocybin)
Magic mushrooms contain psilocybin, which the body converts to psilocin. Like LSD, physical dependence is uncommon, but people can still run into problems if they use them to cope, take larger doses than intended, or feel emotionally unsettled afterwards.
What it looks like: dried mushrooms, sometimes mixed into food or drinks.
How it affects you: altered perception, nausea, emotional intensity, changes in reality-testing.
How long it can be detectable: often up to 24–48 hours in urine.
10. Poppers (alkyl nitrites)
Poppers are inhaled chemicals that cause a brief rush by widening blood vessels. Because the effect is short-lived, people may keep using them in quick succession. They’re not usually linked with dependence in the same way as stimulants or opioids, but they can still cause harm in the wrong situations.
What it looks like: small bottles of liquid, often sold as “room odouriser” or similar.
How it affects you: head rush, warmth, dizziness, headache.
How long it can be detectable: effects are brief and they’re not typically included in standard drug screens.
If this list has felt uncomfortably familiar, you’re not alone. What matters isn’t the label, it’s whether substance use has started to feel difficult to control, or is affecting your health, relationships, work, or mood.
Smarmore (part of Castle Health) has supported people since 1988. If you want to talk things through, a confidential assessment can help you understand what’s going on and what your options are.
Call 041 986 5080 for further support.
