See IRS guidance on Medical and Dental Expenses, including insurance premiums
I think the expenses are only deductible to the extent they exceed 7.5% of your adjusted gross income. So if your AGI was, say, $40,000 and you had $3,000 in total eligible medical expenses, you can't deduct a dime. Sorry.
Straight from the horse’s mouth
Insurance premiums paid by an employer–sponsored health insurance plan are deductible (possibly, see above) if included in Box 1 of your W-2. If the insurance premiums were not included in your Box 1, W-2, then they were taken out of your paycheck on a pre-tax basis, and thus served to reduce your overall taxes.