What is the safest alternative, herbal or otherwise, to medicines like Viagra (sildenafil) etc. To treat ED?

Erectile dysfunction. Some men cannot/should not take Viagra & its competitors to treat erectile dysfunction b/c they're also taking nitrates for angina (chest pain) or heart disease. In this avoid, try to avoid herbal options touted as miraculous as these dietary supplements are often laced w/sildenafil or sildenafil-life products. Alprostadil whether intraurethral or intracavernosal is approved. Vacuum pumps & rings.