The herbal stuff if you legitimately have any kind of ED at all is not effective. If you are functioning perfectly and want a "boost" maybe, but if there is any actual problem it is a waste of money.
The orals Sildenafil Citrate (Viagra), and Vardenafil (Levitra) function in exactly the same manner. There can be dangerous side effects regarding hearing and vision with both. Most who use these two tend to find Viagra to be more potent, but there is a problem with Sildenafil Citrate in that it can give you an erection that is great, but, it can also make it impossible for you to ejaculate. If you are aware of this up front you can survive it, but, make dead certain that if this one shows up that you are ready to get the workout of your life. Tadalafil (Cialis) operates in a different manner. The worst side effect from this is acid reflux/heartburn. Some also complain of a backache. The acid reflux can be dealt with easily by taking an OTC preparation for about 72 hours starting about 4-6 hours after you take the Cialis. Cialis is also cumulative and if taken daily the erectile effect in some individuals builds to a higher level. This was the reason for the daily Cialis at a reduced dosage.
I am on injectable ED meds, but discovered that once I was placed on male HRT that the orals became at least somewhat effective again and I do not need the injections as much as I used to.
If you have anything major or regular not happening below the belt the best route by miles is the injectable. You will need to find a specialist in male reproductive issues and an MD willing to listen to you. Most MD's do not know crap about injectable ED meds and actually present mis-information. If purchased in bulk injectable is actually cheaper than legitimate orals.
Because injectables are not as a whole systemic (they act locally) if used properly at the right dosage this is the most effective and safest method. It also is sex on a level that you only dreamed of as a teenager.
Remember that you need to have a number of things just right for the best performance.
Testosterone levels must be above a certain level to work right.
Testosterone Conversion to DHT must be working correctly.
Estrogen levels in the male bloodstream must be below a certain level to work right.
The final one in men is an elevated prolactin level. If this is high it reduces erectile capability, it also increases your recovery time killing your sex drive for "sloppy seconds". All can easily be dealt with by a male reproductive specialist who very thoroughly understands all of the failures which create E.D..