Is penicillin effective

You need to be more specific in what you're asking. Is penicillin effective against *what*? There are several types of "cillins" and two major types of "Penicillins". They are mainly used for Group A strep infections, (strep throat, tonsillitis) pneumoccocal infections (pneumonia) , rheumatic fever and some other systemic (in the body) infections (such as gonorrhea and other sexually transmitted diseases). Unfortunately, because people do not take their prescribed doses correctly and since doctors have been giving people antibiotics to people for colds and flu, which do not respond to antibiotics, a lot of the types of germs that ARE susceptible to antibiotics have become immune the "older" ones like penicillin. Now the phamaceutical companies have to come up with stronger, different types of antibiotics to kill these "super bugs" that have mutated and become resistant to drugs like penicillin. So...depending on what type of infection you have, penicillin may or may not be effective.