According to TurboTax itself:
Can I deduct medical expenses that were paid with an HSA, MSA, FSA or HRA?
No, you can't deduct medical expenses that were paid with a health savings account (HSA), medical savings account (MSA), flexible spending account (FSA) or health reimbursement account (HRA). These are all pre-tax accounts, and you can't deduct medical expenses that were paid with a pre-tax account.
When you use a pre-tax account to pay for medical expenses, you're paying with tax-free money. You're not allowed to deduct tax-free money because it's considered double-dipping.
With the increased standard deduction starting in tax year 2018, the chances of being able to deduct medical expenses is significantly lower. Taking the medical expenses out of a pre-tax account is more beneficial to the taxpayer than taking the expenses as a deduction in the event you take the standard deduction
