Detailed answer

Performing a patch test before using a new serum is important to check for any adverse reactions or allergies. To do a patch test, apply a small amount of the serum on a small area of your skin, preferably on the inside of your wrist or behind your ear. Leave it on for 24 hours and monitor for any signs of irritation, redness, swelling, or itching. If there are no negative reactions during this time, it is generally safe to use the serum on your face. Patch testing helps identify potential skin sensitivities and minimize the risk of an adverse reaction on your face, where the skin may be more sensitive. Keep in mind that while a patch test can be helpful, it does not guarantee that you won't experience any issues when using the serum on your entire face. If you have a history of sensitive skin or allergies, it is especially important to conduct a patch test and consult with a skincare professional if needed.