I was prescribed 100mg spironolactone for acne and hair loss. I took it for 4 days and had very bad insomnia. Stopped for a week and then restarted at lower dose for 4 days and the insomnia returned. Have been off it for 10 days and still have bad insomnia unless I take a prescription sleep aid. Have never had insomnia before taking this medication. Saw endocrinologist and GP and none were familiar with this side effect from spiro.