Benzodiazepines: MSJ/Diazepam guide

Street benzos like MSJs and other non-prescribed pills are behind a rise in overdose deaths. This guide shares practical, non-judgemental advice to help people stay safer and understand the risks.

What are street benzos?

Street benzos—also called MSJs, blues, vallies, scoobies, and street Valium—refer to benzodiazepines bought online or obtained without a prescription. They can be real, fake, or novel drugs that imitate legitimate medicines.

They’re usually cheap, easy to get, and may be sold in blister packs or pill containers designed to look safe and official. Common markings include ‘DAN 5620’, ‘10’, ‘T-20’, ‘TEM 20’, ‘Bensedin’, and ‘MSJ’.

Street benzos are unpredictable in both content and strength. Some contain novel psychoactive substances (NPS) like etizolam, flualprazolam, or phenazepam, which are not licensed in the UK and can be much stronger than diazepam.

In 2024, the UK classified 15 more novel benzodiazepines as Class C drugs. Some of these, like bromazolam, have been found in tablets marked ‘MSJ’ or sold as diazepam. These substances may be stronger than expected and increase the risk of overdose—especially when mixed with alcohol, opioids or GHB. Read more on GOV.UK.

What are MSJs?

MSJs are blue diazepam tablets stamped with 'MSJ' on one side and a break line on the other. They're produced by MSJ Industries, a subsidiary of Sri Lankan manufacturer J.L. Morison Son & Jones (Ceylon) PLC. Though legitimate, they're being diverted into the illicit market.

Small, blue, professionally pressed pills (approx. 6mm x 1.5mm)
Often referred to as MSJs, vallies, blues
Available online through unauthorised sources
Illicitly sourced from manufacturers in Sri Lanka, India, China, Thailand, and elsewhere

Due to illicit production and lack of quality control, MSJ tablets sold on the street can contain anywhere from 8mg to 30mg of diazepam despite being marketed as 10mg, making dosing unpredictable and dangerous.

Types of benzodiazepines

Different benzodiazepines vary in strength, duration and effect. Common types include:

Diazepam (Valium)
Temazepam (Restoril)
Alprazolam (Xanax)
Lorazepam (Ativan)
Chlordiazepoxide (Librium)
Flubromazolam
Flurazepam (Dalmane)
Phenazepam

Not all benzos are equal—10mg of one type may not be equivalent to 10mg of another.

Effects of diazepam

Diazepam is a long-acting benzodiazepine used for anxiety, muscle spasms, and insomnia. Its effects can include:

Drowsiness and sedation
Muscle relaxation
Confusion and memory loss
Dizziness and impaired coordination

Effects may last into the next day, especially when combined with alcohol. Long-term use increases the risk of dependence and withdrawal.

Side effects

Common side effects:

Drowsiness, confusion, dizziness
Light-headedness, blurred vision
Muscle weakness, slurred speech

Less common side effects:

Skin rashes, tremors, headaches
Sexual dysfunction
Low blood pressure, digestive problems
Difficulty urinating or incontinence

Rarely, paradoxical effects like aggression or disinhibition may occur—especially when mixed with alcohol or other drugs.

Mixing benzodiazepines with other drugs

Combining benzos with other depressant drugs increases overdose risk:

Alcohol: Increases sedation and impairs judgement. Risk of blackout and poor decision-making.
Opioids (heroin, methadone): Strongly suppresses breathing—leading cause of overdose deaths.
GHB/GBL: Even hours apart, the combined sedative effects can be fatal.
Gabapentinoids (pregabalin, gabapentin): Reduce opiate tolerance, increasing overdose potential.

⚠️ Warning: Some fake benzos contain fentanyl or nitazenes

There have been reports of fake benzodiazepines contaminated with strong synthetic opioids like fentanyl or nitazenes. These can cause sudden overdose, even in small amounts. There's no way to see or taste these substances, so the risk of taking them unknowingly is real.

If you’re using benzos—especially street pills—go slow, don't use alone, and carry naloxone if you can. It won't reverse a benzo-only overdose, but it can save a life if someone's taken drugs containing fentanyl or nitazenes.

Overdose and withdrawal

Overdose signs

Unconsciousness
Slow or irregular breathing
Pale lips or skin, vomiting
Cold, clammy skin

If someone has also taken opioids, use naloxone if available—but call 999 in all cases.

Withdrawal symptoms

Stopping suddenly can cause:

Severe anxiety and panic
Shaking, sweating, confusion
Seizures and hallucinations

Withdrawal should be medically supervised. Symptoms can start within hours and last several days.

How are illicit benzodiazepines supplied?

Most legal benzos are prescribed and dispensed by pharmacists. Street benzos may be:

Diverted from legal prescriptions
Bought online, including the dark web
Distributed via social media apps (Snapchat, WhatsApp, Telegram, etc.)

Some are made to look legitimate, but contain unknown or highly potent substances. Public Health England has warned about pills with markings like ‘DAN 5620’, ‘10’, ‘T-20’, ‘MSJ’, and ‘TEM 20’ due to hospitalisations and deaths.

Reducing risk: harm reduction advice

Start low, go slow – dosage varies.
Don’t mix with alcohol or other sedatives.
Don’t use alone – have someone nearby.
Avoid daily use to reduce dependence.
Don’t inject. If you do, don’t share or reuse.
Never stop abruptly—seek medical advice to taper safely.
Don’t drive or operate machinery while affected.

The law (UK)

In the UK, benzodiazepines without a prescription are Class C drugs.

Possession: Up to 2 years in prison, a fine, or both
Supply: Up to 14 years in prison, a fine, or both

If prescribed, you can legally possess and use them—but selling or sharing your supply is still illegal.

Raising awareness and sharing accurate information is one of the best ways to reduce harm. Services can order our benzodiazepine information and awareness booklet here, or use this guide to support people who use benzos—or anyone who needs to understand the risks and effects more clearly.

Help and support

For more information, advice, or support with benzodiazepine use, visit:

Talk to Frank – 24/7 national drug information
Release – Legal advice for people who use drugs
GOV.UK: take‑home naloxone – Guidance on naloxone supply and overdose prevention
WEDINOS – UK-wide drug‑checking data, including benzodiazepine substitutions
Mind – Mental health support during withdrawal or medication use