The use of “Head Shop” compounds has received much media attention lately. There is very little research in the current literature with regard to the extent of the usage of these substances amongst the drug using population in Ireland. We conducted a study to examine the extent of the usage of Mephedrone, Methylone and BZP amongst attendees of Methadone maintenance programs at the DTCB. Two hundred and nine samples in total were tested. The results showed significant usage of these compounds amongst this cohort of drug users, with 29 (13.9%) of samples tested being positive for Mephedrone, 7 (3.3%) positive for Methylone and 1 (0.5%) positive for BZP.