What drugs are safe and unsafe?

Many of them: This is not an easy answer since there are many drugs categorized as unsafe. The american porphyria foundation has good resources on drug safety: http://www.Porphyriafoundation.Com/testing-and-treatment/drug-safety-in-acute-porphyria. Just because a drug may be listed as unsafe doesn't mean it's unsafe for everyone. However, it's important to use caution with any drug that is potentially unsafe.

Drugs: By your question, i assume illicit/illegal drugs. All drugs can cause damage to your body - there is no safe drug. Even medications prescribed by your physician have side effects.

Drugs: Every drug has its risk and benefit , carry potential risk of side affects and interactions . Most side affects are mild and not that common and severe side affects are usually rare . Every person is different and react to medications differently .But in saying that doctors weigh whether risk of giving medications is more or risk of with holding medications is more.