I had one reader write in with a supplement cocktail that he had created to help get him over "middle-aged erectile malaise." He was having mild erection problems but was very disturbed at the problems. To help get him over the problems he was having, he read through my site and then wrote me the following:
"I started the diet Tuesday and, man, I'm starting to feel a difference already. I also made a trip to the grocery last night and the [big-chain vitamin store]. I took one of each of the Horny Goat Weed, Maca, L-Arginine, Pycnogenol and Ginseng and man let me tell ya, there was a difference this morning when I woke up! I felt 16 again ! Lets just say that the wife now knows that it wasn't all in my head. 14 years together can sometimes make ya forget details. Ok enough of that but WOW!"
NOTE: Always check with your doc first. Some supplements, such as Horny Goat Weed, can interact with certain medications for example. Also, this man put all these supplement together at once, but it is better to try one supplement for a two weeks separately and then add another if necessary and so on.
Lets go over the erectile "cocktail" that he created.
2. Horny Goat Weed. HGW (epimedium) has a PDE5 inhibitor in it (Icariin) that works on the enzyme that dissipates Nitric Oxide in a manner similar to Cialis and Viagra. Again, I have given this supplement a fair amount of coverage in my links on Horny Goat Weed and Icariin.
3. Korean (Panax) Ginseng. Production of Nitric Oxide by the endothelium is only step one in the erectile process. As the Nitric Oxide spreads into the blood and smooth muscle cells. Once inside the muscle cells, it triggers the release of an enzyme called guanylyl cyclase that in turn increases cGMP levels and it is cGMP that induces the relaxation response in your arterties, allowing them to expand and blood to enter the penis for an erection. What does this have to do with Ginseng? Several studies have shown that Ginseng increases cGMP. For more information, see my links on Ginseng and Erectile Dysfunction and The Many Benefits of Ginseng.
4. Pycnogenol. Pycnogenol works on yet another pathway. Nitric Oxide is released in the endothelium by shear forces and from various receptor sites, acetylcholine probably being the most prominent. Pycnogenol boosts significantly the Nitric Oxide released due to its action on this acetylcholine pathway.  This same study found a 42% increased relaxation of the arteries from Pycnogenol as compared to controls.  (Read this link on Pycnogenol and Erectile Dysfunction for more details.)
5. L-Arginine. L-Arginine is the precursor, i.e. the building block for Nitric Oxide and so it would stand to reason that consuming L-Arginine directly would increase Nitric Oxide levels. ADMA competes with L-Arginine and so consuming L-Arginine also increases the all-important L-Arginine to ADMA ratio for middle aged and beyond males. CAUTION: Please read my L-Arginine Discussion for potential side effects with L-Arginine.
So taking a supplement cocktail makes some sense in that these enhance your artery-relaxing, erection-boosting at every step along the way. Of course, for many guys this may be overkill because improving just one or two pathways may be sufficient.
In fact, the most important point in the regard is that many foods boost Nitric Oxide as does exercise. Thus, taking supplements for many guys is simply a cheap substitute for eating right and exercising. However, some guys need some short term help while they're getting back in shape and transitioning their diet and a cocktail such as the above may be worth considering.
NOTE: Putting together several synergistic supplements to improve your sex life is the subject in the latter half of my book Peak Erectile Strength Diet .