lake What are the most effective low cost weight loss supplement?

I have already adjusted my diet and increase my caloric burn during the day. I have an event coming up and based on my current projections ( enough to chart on an Excel spreadsheet) I am not going to reach my goal in time. Anything that could provide a boost would be great. Only product that ever worked for me was ephedrine, but now that you can only get in on the internet, from producers I am not familiar/confident with, I am not sure what products are truly effective.there