Unfortunately, Penicillin is not effective for Acne. The bacteria that is involved in Acne is p. acnes. (Propionibacterium acnes).
This special type of bacteria is sensitive to a family of antibiotics called tetracyclines especially minocycline (Commercial names; Dynacin, Minocin, Solodyn). These bacteria are not sensitive to penicillin. Interesting fact; these p. acnes bacteria contain chemical compounds that are sensitive to blue light. Thus one of the ways to destroy them is to use high-intensity blue light (Acne phototherapy).
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