Metformin can cause rare severe skin reactions.
87 citations,
October 1997 in “JAMA” Some vaccines might rarely cause hair loss, more research is needed.
January 2009 in “Reactions Weekly” A man had an allergic skin reaction on his penis from a hair loss medication, which improved after stopping the medication.
6 citations,
September 1988 in “Drug intelligence & clinical pharmacy” Minoxidil caused a severe rash in a patient, which improved after stopping the drug.
63 citations,
March 1995 in “International Journal of Dermatology” Some drugs can cause hair loss, and stopping these drugs often leads to hair regrowth.