Medical and Dental go on schedule A as personal expenses if you itemize deductions. You can deduct Insurance Premiums. Or are you asking about health insurance for your employees?
For your own Self Employed Health Insurance you can deduct it but it doesn't go on schedule C. It goes on Schedule 1 line 16 and is directly deducted from your total income.
Where to enter self employed self employed health ins
https://ttlc.intuit.com/community/entering-importing/help/where-do-i-enter-my-health-insurance-premi...
