Fentanyl is a very strong opioid. This page explains what it is, why it carries a high risk of overdose, and what you can do to keep yourself and other people safer.
What is fentanyl?
Fentanyl is a synthetic opioid, which means it is made in a laboratory. Doctors prescribe it for severe pain, usually as a patch, lozenge or injection.
It is also made and sold illegally. Illegal fentanyl is the main concern on this page. It is around 50 times stronger than heroin, so a very small amount can cause an overdose.
Fentanyl is a Class A drug. It is one of a group of strong synthetic opioids that also includes nitazenes, which have been found in drugs sold in the UK.
Why is it a risk?
You may not know you are taking it. Fentanyl and other synthetic opioids are sometimes mixed into heroin, or pressed into fake tablets sold as oxycodone, diazepam or other medicines. You cannot see, smell or taste them.
It is not mixed evenly. One part of a batch can contain far more than another. A dose that was fine yesterday could cause an overdose today.
It works fast. Fentanyl can slow or stop breathing within minutes, which leaves less time to get help.
Tolerance does not fully protect you. Even people who use opioids regularly can overdose on a small amount.
Brief skin contact with fentanyl powder will not cause an overdose. You do not need to be afraid of helping someone.
Reducing the risk
The only way to avoid the risk completely is not to take drugs that could contain fentanyl. If you are going to use, these steps can lower the risk:
- Try not to use alone. If you are with others, take turns so someone is always able to respond.
- Start low and go slow. Take a small test dose first and wait before taking more, especially with a new batch or a new supplier.
- Carry naloxone. Naloxone is a medicine that temporarily reverses an opioid overdose. Make sure the people around you know where it is and how to use it.
- Avoid mixing. Using opioids with alcohol, benzodiazepines, pregabalin or gabapentin greatly increases the risk of overdose.
- Take extra care after a break. Your tolerance drops quickly after time in hospital, prison, detox or any period of not using.
- Only take tablets that came from a pharmacy. Tablets bought online or from a dealer may not contain what the packaging says.
Test your drugs. Fentanyl test strips are available free from Wirral Ways. They can show if fentanyl is present, but they are not a guarantee. A strip only tests the small sample you put on it, and it will not detect nitazenes or other synthetic opioids. Even after a negative result, start low, go slow, and keep naloxone close.
Signs of an overdose
Someone may be overdosing if they:
- cannot be woken, or do not respond to your voice or touch
- are breathing very slowly, shallowly, or not at all
- are making snoring, gurgling or choking sounds
- have blue or grey lips and fingertips
- have very small (pinpoint) pupils
- have pale, cold or clammy skin
What to do if someone overdoses
- Call 999 and ask for an ambulance. Say the person is unresponsive and not breathing properly.
- Give naloxone if you have it. Follow the instructions in the kit. Anyone can give naloxone in an emergency.
- If they are breathing, put them in the recovery position (on their side, with their head tilted back to keep the airway open).
- If they are not breathing, follow the instructions from the 999 call handler. They will talk you through what to do.
- Give another dose of naloxone if there is no response after 2 to 3 minutes. Fentanyl is strong, so more than one dose may be needed.
- Stay with them until help arrives. Naloxone wears off, and the overdose can return.
Do not put the person in a bath, give them anything to eat or drink, or leave them to sleep it off.
Get support
You do not have to be ready to stop using to talk to us. We offer free, confidential support, including harm reduction advice and naloxone kits with training on how to use them.
Phone: 0151 556 1335
Email: wirral.services@cgl.org.uk
Website: www.wirralways.org.uk
If you are worried about someone else’s drug use, we can support you too.
Last Updated on 2 October 2026