If your thigh highs are slipping down, you may have a build-up of oil and/or soap residue on the silicone stay-up band. There is an easy fix. Either use an alcohol swab or cotton ball dipped in isopropyl alcohol to clean the silicone ridges on the inside of the top band. This will remove the oils and anything else that may be preventing it from clinging to your leg. Over time the band of the thigh high may loosen up a bit. It could also be an indication that it’s time to buy a new pair. Try cleaning with alcohol first.