I ain't tipping for tox!

Yesterday I got dysport in my forehead, 11's, crow's feet and lip flip done (my usual). When I was checking out, I was prompted to leave a tip. For reference, 20% would be close to $200 extra.... I was kind of stopped in my tracks because I hadn't been asked before. Yes, we tip for nails and hair, and waxes and facials, but when it comes to injections, it just feels wrong. It's technically a medical procedure, and because they are setting their own price points, which are obviously a bit expensive, adding a tip would actually price me out of being able to afford the procedure in the first place. Of course, being me, I wasn't able to walk away comfortably/100% guilt-free...

Thoughts?

UPDATE: it seems the issue here is that because I was at a medspa, the tipping prompt is automatic. I still think that if they’re not able to bypass this page internally for Botox, the front desk absolutely should mention that it’s not expected, not just leave it up to you to feel uncomfortable or be unsure. Thanks to all the ladies who responded. May all your foreheads remain tight, lifted and shiny!!!