Chemical A has not been tested in large-scale clinical trials in the UK. It is important for drugs to be tested in clinical trials before the drugs are approved for use by the public. Give two reasons why.

Clinical trials are essential for drug development. The primary reasons are: 1. **Safety:** To ensure the drug is safe for humans and to identify any potential harmful side effects or toxicity. This prevents causing harm to patients. 2. **Efficacy:** To confirm that the drug is effective in treating the target disease or condition. It needs to be proven that the drug actually works as intended. 3. **Dosage:** To determine the most effective and safe dosage to administer. Too little might not work, and too much could be harmful.