List any four characteristics of an ideal contraceptive?

An ideal contraceptive is safe, effective, reversible, and easy to use/affordable. 

Safe: minimal side effects; suitable for long-term use.

• Effective: high protection against pregnancy when used correctly.
• Reversible: normal fertility returns after stopping.
• Easy & acceptable: simple to use, low cost, culturally acceptable, does not interrupt intimacy.

Other desirable features: protects against STIs (e.g., condoms), compatible with breastfeeding, few medical contraindications, widely available, and requires little clinical supervision.