Start with information
If you're going to use substances, knowing what you're taking and how to reduce the risks is the single most important thing you can do. Here are the fundamentals.
Test your substances
You can't know what's in a substance by looking at it, tasting it, or relying on the person who gave it to you.
•Drug testing services exist in many countries. In the Netherlands, DIMS offers free testing at 33 locations.
•Reagent test kits (like Marquis, Mecke, Simon's) can identify some substances at home. They're not as accurate as lab testing, but they can catch dangerous substitutions.
•Fentanyl test strips can detect fentanyl contamination. These are especially important for any powder or pressed pill.
Start low, go slow
•If you're trying a new substance or a new batch, take a smaller dose first and wait to feel the effects before taking more.
•Everyone's body is different. What works for someone else may be too much for you.
•The onset time varies by substance and route of administration. Oral doses can take 30-90 minutes to kick in — don't redose just because you don't feel it yet.
Don't mix without checking
Mixing substances multiplies the risk. Some combinations are genuinely dangerous, even if each substance is relatively safe alone.
•Use the interaction checker before combining anything.
•Alcohol with other depressants (GHB, opioids, benzos) is one of the most dangerous combinations.
•Stimulant + depressant combos can mask warning signs of overdose.
Stay hydrated — but don't overdo it
•Dehydration is a real risk, especially with stimulants and in hot environments (clubs, festivals).
•Aim for regular small sips — about 500ml of water per hour if you're active.
•Don't over-hydrate. MDMA in particular can cause a dangerous condition called hyponatraemia (water intoxication) if you drink too much water. Sip, don't chug.
•Electrolyte drinks or a salty snack can help maintain balance.
The buddy system
•Never use alone if you can avoid it. Have someone present who is sober or less intoxicated.
•Agree on a plan: what will you do if someone feels unwell? Who calls for help?
•Share what you're taking and how much — this information could be critical in an emergency.
Set and setting
•Your mindset and environment affect your experience significantly.
•Being in a safe, comfortable place with people you trust makes everything safer.
•If you're feeling anxious, unwell, or in a bad headspace, it may not be the right time.
After use
•Eat something. Your body needs fuel to recover.
•Rest. Sleep is the best recovery tool.
•Be gentle with yourself in the days after. Some substances affect mood for several days.
•Avoid redosing or bingeing — the risks increase substantially the longer a session goes.
Know when to get help
If something doesn't feel right, trust your instincts. Seeking help early is always better than waiting.
•Chest pain, difficulty breathing, or irregular heartbeat → call emergency services.
•Extreme anxiety or paranoia → go somewhere calm, tell someone, and consider calling a helpline.
•If someone is unconscious, put them in the recovery position and call for help.