Why the IRS Says No to Most Supplement Write-Offs
Under IRC Section 162, a business expense must be ordinary and necessary for your trade. Supplements fail this test in most audits because they carry an inherent personal benefit: they support general health and fitness, not just your specific job as an athlete. The IRS and Tax Court apply this same logic to gym memberships, personal trainers used outside team facilities, and specialty diets. Even though your career depends on your body performing at an elite level, the deduction gets denied because a non-athlete could buy the same tub of whey protein or the same multivitamin for the same reason: staying healthy.
This catches a lot of NIL and pro athletes off guard, especially those filing a Schedule C for endorsement or appearance income. An advisor who lets you write off creatine, pre-workout, or recovery supplements as a straight business expense is setting you up for a disallowed deduction if the IRS ever looks closely.
The Narrow Path: Medical Expense Deduction
There is one legitimate route, but it is limited. If a licensed physician diagnoses a specific medical condition and prescribes a supplement as treatment (not general wellness), that cost can be claimed as an itemized medical expense on Schedule A. The catch: only the portion of your total medical expenses exceeding 7.5% of your adjusted gross income is deductible. For an athlete with a multi-million dollar season, that threshold is often impossible to clear unless you have other major medical costs the same year.
Over-the-counter vitamins, protein powder, and general performance supplements almost never meet this bar because they are not prescribed treatment for a diagnosed condition. Team-mandated supplements provided and paid for directly by your team or league are different: those are typically not income to you and never something you need to deduct in the first place.
What Actually Holds Up in an Audit
Expenses that survive IRS scrutiny share one trait: they would not exist but for your job. A registered dietitian hired specifically to build a performance nutrition plan tied to a contract clause might be defensible. A specific supplement required and documented by a team's medical staff, purchased separately from personal use, has a stronger case than a monthly Amazon order of gummy vitamins. Keep receipts, a note of the business purpose, and any team or league documentation separate from personal purchases.
Given how often agents and advisors mishandle these gray-area deductions, it is worth having a tax professional review your Schedule C write-offs each season rather than assuming last year's playbook still applies.
Bottom Line
Treat general supplements as a personal expense, not a tax write-off. Save the deduction conversation for prescribed treatments tied to a documented medical condition, and lean on your team or league's own supplement programs when possible instead of trying to deduct your own.