Don't fuck with it. Tampering with fentanyl patches is like playing Russian roulette.
Fentanyl is a cold, merciless, sometimes overwhelmingly nauseating, potent opioid, you can totally tell its synthetic and has been designed to manage severe chronic pain and when it's used in the medical setting, your life lies on your vitals which are monitored particularly ventilation / blood O2 concentration.
Some say it feels like menopause hot flashes. Not sure how this is desirable for anyone. This opioid is not to be abused, the risk of accidental overdose are too high. Simple risk vs reward. Risk takes out reward by a fucking murderous landslide.