Severe muscle cramps nighttime in my legs have recently been wrecking my sleep. After reading up, I discovered that pain in legs can be a side effect of tadalafil/ cialis.
After quitting, the cramps rapidly receeded and after less than a week no longer appear.
I had been taking 5 mg daily for 4-6 months when the cramps started, in different places each time, on either leg. Mainly calves, occasionally thigh or foot.
Alas, all is not gold that glitters.
I will try sildenafil instead. That also has muscle pain as a possible side effect, but at least it is not specified to be in the legs.