Public Health · Harm Reduction
This guide provides evidence-based harm reduction information to help people who use drugs reduce the risks associated with their use. All information is based on established public health research and the work of leading harm reduction organisations.
Call emergency services immediately (911 in the US / 999 in UK / 112 in EU). If opioid overdose is suspected: administer naloxone (Narcan) if available, perform rescue breathing, place in recovery position. Do not leave them alone.
Never Use Alone Hotline (USA): 1-800-484-3731 | Never Use Alone UK: 0800 587 0849
Core Principles
Use reagent test kits (Marquis, Mecke, Mandelin, Simon's, Froehde) to identify substances before use. Fentanyl test strips are essential for any substance that could be contaminated — a lethal dose is invisible and odourless. Services like DanceSafe (dancesafe.org) provide affordable test kits and mail-in drug checking.
Always begin with the smallest effective dose, especially with new batches or unfamiliar substances. Potency varies even within the same batch. Allow adequate time between doses — many overdoses occur when users re-dose before the first dose has taken full effect. This is especially critical with MDMA, GHB, and edibles.
Have a trusted, sober person present. If that is not possible, use the Never Use Alone hotline. Keep naloxone (Narcan) accessible and ensure someone nearby knows how to administer it. Naloxone is available without prescription at many pharmacies in the US, UK, and EU.
The most dangerous drug combinations involve mixing depressants. Never mix opioids with benzodiazepines, alcohol, or other CNS depressants — this combination is responsible for the majority of overdose deaths. The TripSit Combo Chart (combo.tripsit.me) provides a comprehensive interaction guide for all substance combinations.
Tolerance drops significantly during any break in use — even a few days off opioids can reduce tolerance dramatically. Returning users who use their previous dose are at extreme overdose risk. Starting at 10-25% of your previous dose after any break is strongly advised.
Providing harm reduction information saves lives. The goal is to reduce negative consequences for people who will use drugs regardless. Abstinence is the only guaranteed way to avoid drug-related harm, but for those who choose to use, evidence-based harm reduction dramatically reduces risk.
Substance-Specific Information
The following provides brief harm reduction information for commonly encountered substances. This is not a complete guide — always research thoroughly using the external resources listed below.
Generally considered low acute toxicity. Risk of dependency with heavy use. Edibles have delayed onset (30–120 min) — avoid re-dosing. Avoid mixing with alcohol. Not recommended for those with personal or family history of psychosis.
Test with Marquis reagent (should turn purple/black). Dose: 75–125 mg. Avoid redosing more than once. Stay hydrated but do not over-hydrate (hyponatremia risk). Avoid with SSRIs (serotonin syndrome risk). Recommended interval: 1–3 months between uses.
Test for levamisole and fentanyl contamination. Avoid mixing with alcohol (cocaethylene formation increases cardiac risk). Never use alone. Highly addictive — risks increase significantly with frequency of use. Nasal irrigation reduces harm from insufflation.
Highest overdose risk of any class. Always test for fentanyl — assume contamination. Use a fentanyl test strip for every batch. Keep naloxone within reach. Never use alone. IV use carries infection risk — use sterile equipment and never share needles. Tolerance drops dangerously after abstinence.
High addiction potential. Cardiovascular strain — avoid if heart conditions present. Sleep and nutrition are critical — meth significantly suppresses appetite and disrupts sleep. Avoid prolonged runs. Use clean equipment if injecting. Regular drug breaks help reduce physical and psychological dependency.
Very low physiological toxicity. Set and setting are critical to experience quality. Do not use if predisposed to psychosis. Avoid mixing with lithium (seizure risk). Avoid alcohol. Have a trusted sober trip-sitter. HPPD risk with heavy use. Most psilocybin mushrooms are accurately identified by appearance — test strips available.
Extremely dangerous to combine with any other depressant, especially opioids and alcohol. High dependency and tolerance risk. Withdrawal can be life-threatening — never abruptly stop after heavy use. Taper slowly under medical supervision if dependent. Tolerance forms quickly — limit to prescribed/occasional use.
Extremely narrow margin between recreational dose and overdose. Precise dosing essential — 1 mL difference can mean unconsciousness. Never mix with alcohol or other depressants. Avoid redosing. Keep timing strict. GBL is prodrug — more potent and faster onset than GHB.
Anaesthetic — can cause loss of consciousness at high doses (k-hole). Avoid mixing with depressants. Risk of bladder damage (ketamine cystopathy) with frequent use — reduces with less frequent use and lower doses. Not physically addictive in the traditional sense but psychological dependency is common.
Emergency Response
Try to rouse the person — sternal rub (knuckle pressed firmly on sternum). Check for response. If unresponsive, proceed immediately.
Open the airway — tilt head back, lift chin. Check for breathing. Look for slow, shallow, or absent breathing. Gurgling sounds indicate the need for rescue breathing.
If breathing is absent or very slow (<1 breath per 5 seconds), give rescue breaths at 1 per 5 seconds.
Call 911 / 999 / 112. Administer naloxone (Narcan) intranasally or via auto-injector. One dose every 2–3 minutes if no response.
Symptoms: Agitation, confusion, rapid heartbeat, high temperature, muscle twitching, excessive sweating, shivering.
Action: Call emergency services immediately. Stop all serotonergic substances. Cyproheptadine may be prescribed in hospital. Cooling measures for hyperthermia. This is a life-threatening emergency.
External Resources