Content reviewed by the PillRelax Healthcare Team | Last reviewed: September 2026
Diazepam (Valium) and Clonazepam (Klonopin) are both benzodiazepines prescribed for anxiety in the UK. While they share a mechanism of action, they differ significantly in potency, duration, and clinical use.
Quick Comparison
| Factor | Diazepam | Clonazepam |
|---|---|---|
| Standard UK dose | 2-10mg | 0.5-2mg |
| Potency (relative) | Lower – 10mg Diazepam = 0.5mg Clonazepam | Higher – approximately 20x Diazepam |
| Onset | 30-60 minutes | 1-4 hours (slower) |
| Duration | 6-12 hours | 12-24 hours (longer) |
| Primary uses | Anxiety, muscle spasm, alcohol withdrawal | Panic disorder, anxiety, epilepsy |
Which Is Better for Anxiety?
Both are effective. Diazepam is often preferred for acute situational anxiety due to its faster onset. Clonazepam’s longer duration makes it more suitable for generalised anxiety disorder or panic disorder where sustained coverage is needed.
Frequently Asked Questions
Can I take Diazepam and Clonazepam together?
No. Combining two benzodiazepines significantly increases sedation, respiratory depression, and overdose risk.
