The doctor's response: It is difficult to give an exact answer to your question, as the "side effects" associated with hard drug use can vary greatly. The risks of having unprotected sex with a user depend on how the drug is used. If the person does not share the equipment used to consume the drug, the risks are lower than if they use the same equipment as others. In the latter case, they may be at risk of contracting STIs (sexually transmitted infections) such as hepatitis and HIV, among others.