Where do I add a business loan and interest?

[Critter]

Ok ... if you took out a business loan for your Sch C business then all you can deduct on the Sch C is the interest that you pay.  The principal portion of the loan is not deducted on the Sch C ... instead what you took out the loan for is the actual deduction.   For example if you took out the loan to pay for inventory then  you deduct the cost of the inventory purchased and you get to take the entire deduction in the year of purchase .... you do not have to wait until you pay off the loan. 

[asapbot]

I am trying to figure out how do I show deductions for a loan I received from my sister in starting my company.  I have 100% ownership.

I started my company in 2017 I spent over $6,500 in 2017 and 2018 getting my company started and afloat, I want to make sure I can right off my invested monies this year instead of show and income?