How long after microneedling treatment (.5mm) can I use *chemical* sunscreen?

Hello there, 
      I would STRONGLY recommend a good physical sunblock, as the long-term effects of chemical sunscreen is not known. That being said, the microneedling injuries should be closed and healed within 24 hours. I would wait another day or so after this since the skin will be more sensitive. You can always try applying a small amount in a test area to make sure you do not get any type of reaction. Hope this helps. 
Sarah RN BSN 

Thank you for your question. I understand your concerns with physical versus chemical sunscreen from a financial standpoint but as far its effects on the skin physical sunscreen is far safer. Keep in mind that you are investing in your skin by spending money on in office procedures and it is just as important if not more important to use the proper skincare products including sunscreen for optimal results from your procedures as well as long term care of the skin.
With that being said, each provider microneedling protocol is different. I like the immediate use of sunscreen but holding off for 72 hours for all other products including makeup in order to allow your skin to heal and prevent breakouts, as well by clogging the pores the procedure creates. If you must use chemical sunscreen, wait 72 hours to do so and make sure to follow up with your provider, as well to ensure you are  healing properly.

Every provider will have slightly different protocols following your microneedling treatment, so it’s best to ask him or her for specific guidelines. You have to be careful about what you put on your skin directly after microneedling, as the microchannels that it creates allows for increased absorption. This is why physical sunscreens are recommended versus chemical SPFs. Physical sunscreens like hats and long clothing are not absorbed into your skin, while chemical sunscreens are. There are now a variety of clear mineral-based sunscreens that don’t leave a white film on your skin.