Penicillin G Penicillin G is an injectable antibiotic that treats a wide range of bacterial infections in animals with the sterile suspension of Penicillin G. Contains 300,000 units/mL of Penicillin for intramuscular injection. Keep refrigerated. This product requires 1- or 2-day express shipping. Prices From:$0.00$8.99 - For more details click here.