I like this product. The ingredients look good and it's nice to have SPF on my lips (an area of my face I often forget). My only issue is the price. Eighteen seems a bit steep for a lip balm, so I leave this one in my medicine cabinet and only use it in the morning after I finish my skincare regimen. The rest of the time I use Jack Black Intense Therapy Lip Balm (Lemon & Chamomile), also SPF 25 which I can apply throughout the day. It is only eight dollars and it seems to stay on a bit longer -- though MD's product is silkier.
I did not love this product. I have not been able to tell if it provides adequate sun protection however it is so light in texture that it seems to disapear almost instantly from my lips. It also seems to have a drying effect on my lips. I may continue to use it as a suncreen, but only on top of some other lip conditioner that provides the lasting moisture I need.