There are two questions here: what can be written off as an ordinary and necessary business expense and what can be written off as a personal medical expense.
Regarding business expenses for the self-employed, it is a little nebulous as to what is considered "ordinary and necessary." If you are an actor and have your hair done for some headshots, that meets the requirement. If you have your hair done because you have to maintain your appearance as you go through life, probably not. Two categories the IRS specifically prohibits taking as business expenses are personal living and family expenses and dues to business, social, athletic, luncheon, sporting, airline, and hotel clubs. Where you draw the line between a personal living expense and an ordinary and necessary business one is a little fuzzy.
As for personal medical expenses, the first thing to note is that very few people are even eligible for these. Your out-of-pocket medical expenses would have to exceed 7.5% of your gross income before you are allowed any deduction and you would have to be itemizing your deductions. Gym memberships are specifically excluded and cannot be deducted. There is not as much gray area in the medical expenses as the IRS does list a number of includable and excludable expenses.
@Freelance
