Could saw-palmetto cause permanent erectile dysfunction?

Probably not: Saw palmetto is a natural plant which has not been documented to cause ed.

Equivocal: Some trials of saw palmetto vs other agents in prostate enlargement did show lowered libido and ejaculatory problems (not erectile dysfunction) with saw palmetto. http://tinyurl.com/kgv9tdc however, patients in these studies also had prostate problems, which makes it harder to attribute cause for these issues. Many were lost to follow up, so we don't know if the difficulties continued.