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GHB/GBL Safety

GHB has one of the narrowest safety margins of any recreational drug. Here's how to reduce the risk.

4 min readReviewed 2026-03-01

Why GHB needs its own guide

GHB (gamma-hydroxybutyrate) and GBL (gamma-butyrolactone, which converts to GHB in the body) have one of the narrowest dose-response curves of any commonly used recreational drug. The difference between a pleasant dose and an overdose can be less than half a millilitre.

This makes GHB one of the highest-risk substances in chemsex and party contexts. Understanding the risks and taking precautions can genuinely save lives.

Critical rules

1. Always measure accurately

Use a syringe or graduated pipette — never pour directly from a bottle.
Strength varies hugely between batches. A "normal" dose from one batch may be an overdose from another.
Start with a low test dose (0.5ml for GBL, 1ml for GHB) and wait at least 30 minutes before deciding to take more.

2. Never mix with alcohol or other depressants

GHB + alcohol is the most dangerous commonly used combination. It's responsible for the majority of GHB-related hospitalisations and deaths.
Also avoid combining with: opioids, benzodiazepines, ketamine, or any other sedative.
Even a small amount of alcohol significantly increases the risk of losing consciousness.

3. Time your doses

Wait at least 2 hours between doses.
Set a timer on your phone. When you're on GHB, your sense of time becomes unreliable.
Write down when you last dosed. If you're sharing with others, each person should track their own.

4. Never let someone else dose you

Always handle your own GHB/GBL.
Know what concentration you're working with (ask the person who provided it).
Don't share drinks that may contain GHB.

Signs of GHB overdose

Sudden unconsciousness — cannot be woken up
Vomiting while unconscious
Very slow or irregular breathing
Seizure-like twitching
Confusion followed by sudden collapse

What to do if someone overdoses

.Call emergency services (112/999/911) immediately.
.Put them in the recovery position — on their side with their mouth pointed downward. GHB overdose often causes vomiting; lying on their back can cause choking.
.Monitor their breathing. If it stops, begin CPR.
.Stay with them until help arrives.
.Tell paramedics it's GHB — this information is critical for treatment.

You will not get in trouble for calling for help.

GBL vs GHB

GBL is a prodrug that converts to GHB in the body. It's stronger drop-for-drop and kicks in faster.
GBL is typically dosed at half the volume of GHB (e.g., 0.5-1ml GBL vs 1-2ml GHB).
GBL has a caustic chemical taste and can irritate the mouth and throat. Always dilute in a drink.
Never confuse GBL and GHB doses — taking a GHB dose of GBL is an overdose.

Dependency

GHB/GBL can cause physical dependence surprisingly quickly, sometimes within weeks of regular use.

Signs of dependence:

Needing GHB to sleep
Using daily or multiple times per day
Anxiety or tremors when you stop

GHB withdrawal can be medically dangerous and may require supervised detox. If you think you may be dependent, talk to a doctor or contact a drug service. They can help safely.

The bottom line

GHB can be enjoyable, but it demands more respect and caution than most substances. Accurate dosing, timing, and never mixing with alcohol are non-negotiable. If you or someone you're with uses GHB, knowing these rules could save a life.

This content is for harm reduction purposes only and is not medical advice. Always consult a healthcare professional. In an emergency, call your local emergency number.

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