The research team also noted that the relaxation response appeared to occur independent of the nitric oxide-cyclic guanosine monophosphate (cGMP) pathway used by the oral ED drugs known as PDE5 inhibitors. If further testing confirms these assumptions, that would make bromelain yet another form of treatment for ED, one that might help those men who don’t respond positively to PDE5 inhibitors.
https://www.edrugstore.com/blog/erectile-dysfunction/bromelain-why-ed-researchers-are-interested-in-this-natural-enzyme/