Patch testing prior to use is highly advised to see whether any reaction is caused from a certain product.
Patch test for 2 in 1 Eyeliner Adhesive:
Apply the product as directed to a small area (behind the ear) and leave for 24 hours.
If you develop any serve irritation or swelling, rinse off thoroughly with a cleanser.
Cease use and seek medial attention as soon as possible. 
Patch test for iLLscara:
 Apply the product as directed to a small area (behind the ear) and leave for 24 hours.
If you develop any serve irritation or swelling, rinse off thoroughly with a cleanser/cold water.
Cease use and seek medial attention as soon as possible. 
iLuvLash™ is not responsible for any irritation caused.