Please discuss everything with your doctor first.

1. Pomegranate Juice. Drink between 2 and 8 oz. of Pomegranate Juice each day. Pomegranate Juice is King of Cardiovascular Repair:  this magic juice is so powerfully loaded with antioxidants that it has actually partially reversed artheriosclerosis. Furthermore, there is a recent study that shows that Pomegranate Juice actually improves erectile dysfunction and impotence. How does it work its magic? Besides clearing out your arteries, it also lowers inflammation and, most pertinent to your sex life, boosts Nitric Oxide. My advice is heed the words of these researchers, who concluded: "Plasma nitrate and nitrite (NO(x)) levels were significantly increased by PFE (Pomegranate Food Extract) and PJ (Pomegranate Juice)". Yes, Pomegranate Juice should probably be called "Viagra in a Bottle" or "Liquid Sex".  For more information, read this link. 

   Do you know the foods and drinks that increase erection-boosting Nitric Oxide? Check out the Peak Erectile Strength Diet where I show you how to dramatically and naturally improve your erectile strength.

   CAUTION:  Pomegranate Juice has several drug interactions, especially with statins.  Consult your physician if you are taking any medications.
2. Sex.  You probably don't want to hear this, but you really need to have sex.  That is correct - Lack of Sex is a recently discovered strong risk factor for erectile dysfuntion.  So what are you waiting for?  Time to get busy!  (Actually, I know that some of you need some practical ideas for how to get more sex from the woman in your life.  Well, it's not as hard as you might think in most cases.  Here are a few ideas that will definitely help:  Oxytocin, Massage, Pelvic Angle, Tease Her and Increase Her Libido.)
3. Supplements.  Remember that researchers have found a number of inexpensive herbal Supplements that can generally very significantly improve your Erectile Dysfunction, including Pycnogenol, Arginine, Horny Goat Weed, Maca and Ginseng. There are also some less exotic Supplements, such as CoQ10 and Vitamin C, that will help somewhat as well.  Some of these boost Nitric Oxide directly and some keep Nitric Oxide in your system longer.  Either way, they have proven clinical results to help reverse erectile dysfunction (and in some cases libido boosters as well).  Read here for more details.
4. Foods and Drinks.  There are many foods and drinks that dramatically improve Nitric Oxide output and will strongly improve your erections.  For more details read here.

   When does low testosterone cause erectile dysfunction or harden your arteries? 300 ng/dl? 400? Find out what the studies say in Low Testosterone By The Numbers.

5. Exercise. In terms of importance and effectiveness for improving erectile dysfunction, this should probably be at the top of the list. A 2007 John Hopkins Medical School study recently found that men who watched television over five hours per day increased their odds of erectile dysfunction by 300 percent! [2] A study from that same year actually found that lack of exercise was the number one commonality behind the erectile dysfunction and impotence of 388 men. [3] The authors of the study found that "lack of exercise was the most frequent risk factor (82.2%), followed by smoking (55.9%) and the regular use of medications (43.6%). Diabetes was reported by 29.6% of the patients and 14.7% reported hypertension. Other risk factors included drug addiction (7.7%), alcohol consumption (12.6%) and cardiac diseases (5.2%)". 82% of those with erectile dysfunction did not exercise!  As I show, one could easily write the formula, Exercise=Viagra.
6. Gutless.  Get rid of your gut and those love handles.  Obesity is one of the biggest risk factors for erectile dysfunction.  For example, a Chinese study found that a BMI of just 23-25 leads to twice the risk of hypertension (high blood pressure) and high blood pressure is one of the leading indicators for erection problems.  [12]  Other studies have directly found that obesity is a risk factor for erectile dysfunction. [41] In addition, fat cells churn out inflammatory chemicals, which also lead to poor endothelial function and heart disease.  Just as bad, fat cells also pump out extra aromatase leading to excess estrogen, the "female hormone".  The testosterone to estrogen ratio is one of the critical ratios for males and this is one denominator you don't want to mess with. Need some ideas on how to lose weight?  Then read here about How to Lose Weight. Or need some more motivation to lose that spare tire and get rid of your erectile dysfunction?  Then read this link.  
7. Kegel Exercises. These exercises, for your muscles down under, are not just for women:  they can dramatically improve Erectile Dysfunction and impotence.  A regimen of Kegel Exercises can have the Little Guy standing tall and proud in the bedroom.  
8. Mediterranean Diet. The Mediterranean Diet is an extremely heart healthy, cancer-fighting and erectile improving diet. Research has verified the power of this way of eating over and over again.  It is also the diet that is probably the easiest for the typical omnivore to transition into since it does allow some meat and dairy. It is also has many delicious recipes and food combinations.  For more information, please see read my link about the Mediterranean Diet. CAUTION:  Please be cautious about Olive Oil.  See below: this is the one aspect of a Mediterranean Diet that could injure your sex life.
9. Blood Pressure.  High blood pressure (hypertension) is a strong risk factor for erectile dysfunction (and of course heart disease). One study of Greek men with high blood pressure found that 35.2% of males with high blood pressure had erectile dysfunction compared with 14.1% with normal blood pressure. [13]  Yet another study showed that  nearly 70% of men with high blood pressure have some kind of erectile dysfunction. [1]  If you have High Blood Pressure, don't expect to improve your erectile dysfunction without dealing with it first.  Fortunately, there are many natural (and scientific) ways to improve your situation and battle this menace to your sex life and I talk about it here. Again, this shows the all important, Zen-like principal about erectile dysfunction: the heart and the penis are one.  And this is the mantra you need to repeat a hundred times a day: "If it's good for the heart, it's good for the penis; if it's bad for the heart, it's bad for the penis."  Please, please get your High Blood Pressure under control:  it leads to damage of your arterial walls and accelerates arteriosclerosis (among other nasty things).  Blood pressure is such an important topic that I have devoted an entire link to How to Reduce Your Blood Pressure Naturally.  
10. Depression.  Depression can create or exacerbate erectile dysfunction in many ways, including lowering libido and diminishing testosterone.  (Depression will also literally eat away your brain.)  But, even more importantly, Depression has been linked by researchers to heart disease.  In other Depression actually does damage to your erectile strength by damaging your cardiovascular system.  Furthermore, many of the drugs associated with treating Depression are strongly correlated with erectile dyfunction.  Read this link for more details.
11. Metabolic Syndrome.  This disease would better be named Castration Syndrome.  I cover Metabolic Syndrome several times on this site because it is so critical to the health of your heart and your penis.  Metabolic Syndrome is a set of symptoms that includes insulin resistance, high cholesterol, high triglycerides, low HDL (good cholesterol) and high blood pressure.  And, if you have it, you are at much greater risk for both low testosterone and erectile dysfunction.  It is unlikely you will experience significant improvement in your erectile dysfunction unless you tame this beast.  So if you have any of the signs of Metabolic Syndrome, please read this link on Metabolic Syndrome.   
12. HRT. If you are low testosterone, get on HRT (hormone replacement therapy). If Nitric Oxide is King in the Land of Erections, Testosterone is Queen. The problem is that low testosterone guys do not fully activate the dense network of androgen receptors at the base of the penis and then those muscles get out of shape. And trust me - you do not want flabby penile muscles. It is these muscles that constrict and hold the blood in the penis once Nitric Oxide has done its job. If you're not getting nightly erections, you are also not oxygenating the penile tissue, which is also critical for the health of your sex life. Again, get to the doctor and start now if you're low on this precious hormone. Remember that it will probably take anywhere from one to three months for these muscles to build up once you get your testosterone levels to where they should be and actually improve any erectile dysfunction that you may be experiencing. CAUTION:  If you are overweight, have apnea or are trying to have a child, be sure to pin down your doctor about issues surrounding each of these conditions. Read the above link for more details.
13. ADMA. If you want to improve erectle dysfunction, you must consider ADMA.  Researchers have found a direct and strong correlation between increased erectile dysfunction and ADMA (Asymmetrical Dimethylarginine ) levels. ADMA is a Nitric Oxide inhibitor - just that phrase should send a shiver down your spine - and one recent study [20] found that levels were significantly elevated in males with both cardiovascular disease and erectile dysfunction. That is no surprise to anyone on this site, where we emphasize that cardiovascular disease and erectile dysfunction more often that not go hand-in-hand. (Many researchers think that the ratio of arginine to ADMA is a super-critical marker of erectile dysfunction.) But realize that ADMA is a double edged sword to your sex life: it increases artherosclerosis, by aiding LDL to damage the lining of your vascular system, and decreases your biolavailability of Nitric Oxide. This is as ugly as it gets: ADMA sabotages your erections from almost every possible angle - no pun intended. What are the primary causes of elevated ADMA levels? First of all, being overweight. Several studies have found a relationship between weight and ADMA levels and one study found obese women who lost weight reduced their plasma ADMA levels by 25%! [21]  It will probably not surprise you then to learn that Metabolic Disorder has been found recently to be a significant risk factor for increased ADMA levels. [22] Please read my link on Metabolic Disorder for how to diagnose and defeat this multi-tentacled monster. One last risk factor we should mention: elevated homocysteine levels, i.e. make sure you are eating a good diet with plenty of B-vitamins or supplementing with Folic Acid.
14. LDL. This Bad Boy of the lipid profile world has been implicated in a study with erectile dysfunction.  And it's no wonder:  LDL is a well-know arterty clogger. [42]
15. Cycling. Watch out for those bike seats!  Yeah, the urban legend is really true:  several studies have shown that biking can injure the arteries supplying blood to the penis.  Recent research shows that a no nose seat significantly protected bicycle officers who rode many hours throughout the week as part of their job. [24]
16. Smoking.  I almost didn't want to put this one in here.  After all, what person in the 21st century doesn't know that smoking wreaks havoc throughout the body?  But I changed my mind, because what a lot of guys don't know is that cigarrettes greatly increase your risk of erectile dysfunction. For example, two meta-analyses showed basically that erectile dysfunction was TWICE as common in smokers versus non. [19] If you won't quit the habit to save your own life, at least do it for the Little Guy downstairs and improve your erectile dysfunction while you're at it!
17. Marijuana. Please read this link on How Marijuana Can Destroy Your Hormones, Fertility and Lead to Impotence.
18. Probiotics. This has not been proven, but probiotics will likely improve erectile strength.  See my link What Are Probiotics Good For for more details. 
19. Mouthwash.  Watch out for those mouthwashes - they may sabotage your nitrite levels, which are critical for nitric oxide production. See my link on Mouthwash and Your Sex Life for more information.
20. Citrulline. L-Arginine is the precursor for nitric oxide and so one would think this would be an ideal supplement for men struggling with erectile dysfunction.  However, study results have been disappointing and even dangerous for this amino acid. Intrepid scientists have apparently discovered a way around the Arginine-related difficulties by giving study particpants L-Citrulline, a precursor of L-Arginine.[43] The L-Citrulline (1.5 grams/day)  increased overall hardness factor and led to a 70% increase in the number of times of intercourse.