When ever I travel I always bring my owned meds from OZ, I find the med here work differently or weaker to the one from home including the genuine cialis, Viagra, valium etc and it almost the cost as back home. As the op say do not buy med on the street you are definitely wasting your money and you don't know what's in it. I stay at Soi 11 last time the pharmacy next to the near ambassador hotel sell genuine med.