Medical Marijuana Business Deduction Surprise!

Many businesses sell medical marijuana in the retail sector. Of course, having legalized marijuana on a state level, makes this business practice legitimate for state taxes but what about federal taxes? For federal tax purposes, since marijuana is still illegal, it prevents this business from being treated as a real business with deductible expenses. However, and this surprised me, the cost of the drugs, or, rather, cost of goods sold, is the only deductible expense.  Rent is not deductible, counseling services provided are not a deductible expense.