I want liposuction but I'm not able to get a loan. How else would I be able to pay without paying upfront?

Thanks for your inquiry.  You could check in your area if any surgeons accept payments, but I think you will find this is uncommon.  It might be best to save up for the procedure; you will then avoid any interest payments.

Saving a small amount every week is a guaranteed way to achieve your goal.  There may be lending agencies who would loan, but you would have to check with their guidelines.

The majority of doctors will only accept payment up front.  If you can't get financing then you should save as you can.

Their are specific reasons that plastic surgeons collect fees upfront.  This is a common practice.  Since surgery is elective perhaps your best option is to save and then consider the surgery.