Boric acid does not kill bed bugs. It acts as a stomach poison that can kill insects such as cockroaches. Bed bugs, however, consume blood, so they don't ingest the poison.
Washing and drying bedding regularly can reduce the likelihood of a bed bug infestation as can purchasing bed bug proof encasements for mattresses and box springs. To be effective, the encasements must stay on for at least a year. Since bed bugs also hide in surrounding areas, decluttering and vacuuming the floor, bed frame and upholstered furniture can help.
Over-the-counter pesticides tend to be ineffective against bed bugs. Many bed bug infestations require professional treatment. Pest control professionals use a combination of non-chemical and chemical treatments to eliminate bed bugs.