My friend gave a private loan to someone and is asking can she deduct the principal

[Davie White]

My friend loaned someone money for a real estate deal.  The person does pay her back and she did report the interest income.  But she wanted to know if she can deduct the principal amount that she paid to the person off of her taxes since she has to report the interest as income.  Does anyone know the answer to this question?  Please help