Are deductions worthwhile on a Sch. C if you have no profit?

A friend and I were talking about this. He says that there is no reason to do a Sch. C until your business makes money, because the deductions can't do anything to lower your tax bills because it has to come off of income from the business on the Sch. C. Is this correct? Even if you don't make money for a new business yet and its operated out of your home, can't you take deductions for office in the home, business use of the home and that does lower your tax bill?