Here is a recent study with rats that shows the benefits of exercise for ED: (LINK HERE)

Summary Erectile dysfunction (ED) is a major public health problem that seriously affects the quality of life of patients and their partners and its prevalence increases significantly with ageing. In this study, we tested the hypothesis that age-associated decrease in penile endothelial (eNOS) and neuronal nitric oxide synthase (nNOS) activity in aged rats may be increased by regular exercise. A total of 28 young (4 m) and aged (24 m) male rats were divided into four equal groups: group 1 – young control; group 2 – young trained; group 3 – old control and group 4 – old trained group. Groups 2 and 4 rats were trained to swim for 30 min a day and 5 days a week, which lasted 8 weeks. At the end of 8 weeks, rats were sacrificed and penile tissues evaluated for eNOS and nNOS activities. eNOS and nNOS activities were evaluated by immunohistochemistry in paraffinized penile tissues and results assessed semiquantitatively. Results also were compared with healthy age-matched and adult (4 m) controls. Serum level of testosterone (T) was determined using ELISA kits (Beckman Coulter, Fullerton, CA, USA). In penile tissues of aged control rats, eNOS and nNOS staining were weakly positive; however in trained groups, eNOS and nNOS immunoreactivity were increased. In young control group, eNOS and nNOS activities were more intense than aged control. eNOS and nNOS activities were higher in adult trained group than control. Serum T concentrations were significantly higher in young and aged trained group than in control groups. We can suggest that regular exercise upregulates eNOS and nNOS expressions in the aged and young rat penis. Regular exercise may improve penile erection by increasing penile neurotransmitter in both young and aged rats.

Carbon Dioxide – CO2 – is poisonous at high levels; but at low levels, it can support vasodilation. The nice thing about CO2 is that you produce it all the time. Just don’t exhale as much CO2 or inhale as much oxygen, and you will raise your CO2 levels. The body carefully controls these, but you may be able to get some benefit from this.

Once again, I am finding that our medical science is quite primitive, and that some ancient forms of health knowledge – such as yoga and Chinese medicine – may have answers that we are only now discovering. I support Western medicine, but when it comes to something as simple as breathing, we simply haven’t had much interest in this field. However, the more I look into breathing, the more I realize that most people either hyperventilate – breathe in too much oxygen – or don’t expand their lungs fully. So, I am researching this and will report more in the near future.

Fasting – not eating – increases the sensitivity of D2 (dopamine) receptors (in rats), so this may also help in humans.

Study on this:

http://www.ncbi.nlm.nih.gov/pubmed/18305018

Here’s an interesting finding. Chasteberry (Vitex agnus-castus) is said to bind dopamine 2 (D2) receptors. Why is that interesting? Because so does apomorphine, an ED drug.

But it gets even weirder. A low dose of chasteberry binds to D2 receptors – killing desire. But high levels of chasteberry increase desire – by reducing prolactin, the evil chemical that creates the refractory period after orgasm.

But which dose is too little and which is too much?

As it says on Wikipedia (http://en.wikipedia.org/wiki/Vitex_agnus-castus):

The mechanism of action [of chastberry] is not fully understood^[19] but it is assumed that it has dopaminergic effects resulting in changes of prolactin secretion. At low doses, such as might have been used in previous centuries for suppression of sexual desire, it inhibits activation of dopamine 2 receptor by competitive binding, causing a slight increase in release of prolactin. In higher concentrations, as in modern extracts, the binding activity is sufficient to reduce the release of prolactin. A study has found that treatment of 20 healthy men with higher doses of Vitex agnus-castus was associated with a slight reduction of prolactin levels, whereas lower doses caused a slight increase as compared to doses of placebo.^[20] A decrease of prolactin will influence levels of Follicle-stimulating hormone (FSH) and estrogen in women ;^{[citation needed]} and testosterone in men .^{[citation needed]} Dopaminergic compounds (diterpenes with prolactin-suppressive effects that were almost identical in their prolactin-suppressive properties than dopamine itself) present inVitex agnus castus seem likely to be the clinically important compounds which improve premenstrual mastodynia and possibly also psycho-somatic symptoms of PMS.^[21]

Here’s a study that offers a high dose of 480 mg for lowering prolactin:
http://www.ncbi.nlm.nih.gov/pubmed/9021345

From the study:

The effects of three doses of a special Agnus castus extract (BP1095E1)–extracts from 120 mg, 240 mg and 480 mg of drug per day–were examined within the framework of a placebo-controlled clinical study of tolerance and prolactin secretion in 20 healthy male subjects during a period of 14 days. There was good tolerance during the study as regards the following: adverse effects, the effects on blood pressure and heart rate, blood count, Quick’s test, clinical chemistry as well as testosterone, FSH and LH values. During each study phase the 24-hour prolactin secretion profile was measured from the penultimate to the final day, and the amount of prolactin release was monitored an hour after TRH stimulation on the last day. A significant increase in the 24-hour profile was registered with the lowest dose in comparison to placebo, the opposite being the case with the higher doses, i.e. a slight reduction. In contrast to the administration of placebo, the 1-hour AUC after TRH stimulation resulted in a significant increase with the lowest dose and a significant reduction with the highest dose. The results suggest effects of the special Agnus castus extract which are dependent on the dose administered and the initial level of prolactin concentration.

Excessive TNF-alpha levels are associated with ED – so does reducing them help fight ED?

Here’s an easy thing you can do that might work.

I read that 4 grams (4,000 mg) of arginine can help with ED. I have tried arginine in the past but never at this high a dose. But then I read this again, from a reliable medical source, so I tried it last night.

For experimental purposes, I try taking things at night and seeing if there is an effect when I wake up. If I wake up like a regular middle-aged man, then that means no effect. If I wake up like a 16-year-old, then that means it has had an effect.

This morning, after taking 4 grams of arginine last night, I woke up like a 16-year-old.

I can’t say for sure it was the arginine; it may just be a coincidence; it may have been the garlic I have been eating (2 cloves/day, crushed). It may be the exercise I have been doing, or the new sunlamp I use. It may just be springtime. Or all combined. Who knows? But it seemed I had a dramatic benefit from taking a large dose of arginine – the precursor of nitric oxide – right before bedtime.

So, I will try this again tonight, and see if I have the same effect.

In the past, I find sometimes thing work, and then they stop. Maybe I need a higher dose. 5 grams?

In any case, this is something you can try. It’s safe, does not require a prescription, and easy to do. There is even research to back up this approach.

If you try this, let me know what happens.

Here’s an article that studied 5 grams of arginine for ED:

http://www.ncbi.nlm.nih.gov/pubmed/10233492

An interesting study showed that taking SOD — superoxide dismutase — an enzyme that clears up free radicals that can contribute to erectile dysfunction — has some benefit (at least in rats).

Read it here: LINK to article.

The good thing about SOD is that you can buy it at a health food store. The bad news is that SOD breaks down in your digestive tract; so you have to buy a version that is absorbed without being digested. They have these at health food stores. This is one of the supplements I take every night, by the way.

Here’s the experiment I would like: take all of these supplements, and try them one at a time with rats. For example, which would be better – arginine, Viagra, SOD, etc etc.

Erections need nitric oxide, which comes from L-arginine – so taking L-arginine should boost nitric oxide levels and improve erections, right? Except it doesn’t usually work.

Part of the reason is that some of the arginine may be sent on another pathway. So, what’s the alternative?

There is L-citrulline. I always thought L-citrulline was downstream of arginine, but the study below suggests it may be better than arginine. I guess you have to read the article to find out why.

This is -as far as I know – a pretty safe (non-toxic) product that is easily available (my ideal criteria), so it is something you can try. The study below says that it can help. Presumably, it would be a good product to add on to Viagra.

Here is the abstract of the study (you can send the author an email asking for a copy of the article for free):

Cormio L, et al. Oral L-citrulline supplementation improves erection hardness in men with mild erectile dysfunction. Urology. 2011 Jan;77(1):119-22.

Department of Urology and Renal Transplantation, University of Foggia, Foggia, Italy. luigicormio@libero.it

Abstract
OBJECTIVES: To test the efficacy and safety of oral L-citrulline supplementation in improving erection hardness in patients with mild erectile dysfunction (ED). L-arginine supplementation improves nitric oxide-mediated vasodilation and endothelial function; however, oral administration has been hampered by extensive presystemic metabolism. In contrast, L-citrulline escapes presystemic metabolism and is converted to L-arginine, thus setting the rationale for oral L-citrulline supplementation as a donor for the L-arginine/nitric oxide pathway of penile erection.

METHODS: In the present single-blind study, men with mild ED (erection hardness score of 3) received a placebo for 1 month and L-citrulline, 1.5 g/d, for another month. The erection hardness score, number of intercourses per month, treatment satisfaction, and adverse events were recorded.

RESULTS: A total of 24 patients, mean age 56.5 ± 9.8 years, were entered and concluded the study without adverse events. The improvement in the erection hardness score from 3 (mild ED) to 4 (normal erectile function) occurred in 2 (8.3%) of the 24 men when taking placebo and 12 (50%) of the 24 men when taking L-citrulline (P < .01). The mean number of intercourses per month increased from 1.37 ± 0.93 at baseline to 1.53 ± 1.00 at the end of the placebo phase (P = .57) and 2.3 ± 1.37 at the end of the treatment phase (P < .01). All patients reporting an erection hardness score improvement from 3 to 4 reported being very satisfied. CONCLUSIONS: Although less effective than phosphodiesterase type-5 enzyme inhibitors, at least in the short term, L-citrulline supplementation has been proved to be safe and psychologically well accepted by patients. Its role as an alternative treatment for mild to moderate ED, particularly in patients with a psychologically fear of phosphodiesterase type-5 enzyme inhibitors, deserves further research.

This study (LINK HERE) reports that an easy-to-get herb, Maca (Lepidium meyenii), has some mild benefit in humans. Men with ED received 2400 mg of Maca or placebo. The investigators reported that “a small but significant effect of Maca supplementation on subjective perception of general and sexual well-being in adult patients with mild ED.”

It’s funny how once I start one line of research, I find a lot of promising information. I have been looking at arginine for ED. This lead to the question of what happens when we inhibit the enzyme that breaks down arginine – arginase.

Now I find that a company is developing drugs that block arginase. The company is Arginetix Inc, and it is attempting to develop arginase inhibitors for the treatment of pulmonary arterial hypertension (PAH) and erectile dysfunction (ED). They are also exploring the treatment of asthma and atherosclerosis.

A study published in The American Journal of Physiology – Heart and Circulatory Physiology demonstrated that, in a mouse model of ED, treatment with an arginase inhibitor restored the intracavernosal pressure (a measure of erection health) of aged mice to the level of young mice without affecting young mice.

While other companies have worked on arginine as a target, no other group is focusing on arginase. Inhibiting the enzyme increases production of nitric oxide, which is critical for cell signaling, and reduces the production of reactive oxygen, which can damage cells.

For more information, here is a press release from Argenitex: CLICK HERE.

Here is an article about inhibiting arginase: CLICK HERE.

If you want to create your own arginase inhibitor in your laboratory, here’s how: CLICK HERE.

On wikipedia, they have this to say about arginase:

Arginase II is coexpressed with nitric oxide (NO) synthase in smooth muscle tissue, such as the muscle in the genitals of both men and women. The contraction and relaxation of these muscles has been attributed to NO synthase, which causes rapid relaxation of smooth muscle tissue and facilitates engorgement of tissue necessary for normal sexual response. However, since NO synthase and arginase compete for the same substrate (L-arginine), over-expressed arginase can affect NO synthase activity and NO-dependent smooth muscle relaxation by depleting the substrate pool of L-arginine that would otherwise be available to NO synthase. In contrast, inhibiting arginase with ABH or other boronic acid inhibitors will maintain normal cellular levels of arginine, thus allowing for normal muscle relaxation and sexual response.[6] Recent studies have implicated arginase as a controlling factor in both male erectile function and female sexual arousal, and is therefore a potential target for treatment of sexual dysfunction in both sexes. Additionally, supplementing the diet with additional L-arginine will decrease the amount of competition between arginase and NO synthase by providing extra substrate for each enzyme.[7]

You may have heard that Viagra works by raising levels of nitric oxide, which helps erections. But there are other ways of raising nitric oxide levels. Here are some ways to raise nitric oxide levels, which will presumably help your blood vessels and improve erections:

• Take a sauna. Several articles (THIS LINK) show that saunas can raise nitric oxide levels. A hot bath may do the same thing. I found that taking a bath every day helped me after 1 week!
• Get acupuncture, which some authors suggest raises nitric oxide levels in areas near to where acupuncture needles are used (LINK HERE). My guess is that massage would have the same effect.
• Take fish oil (omega 3) (LINK HERE).
• Drink green tea (LINK HERE)
• Take vitamin C

A lot of this research was done in people or animals with blood vessel problems due to conditions such as obesity, high blood pressure, or diabetes. What is interesting is that a lot of tradition approaches – such as saunas – seem to have a scientific reason for improving health. As with all advice on this site, talk to your doctor before you try anything.

I am always ragging on herb/supplement companies that don’t do any research…so I have to report on a study that was actually done, with the supplement Prelox. You can read about it at THIS LINK, in an article that seems actually legitimate. The supplement has two ingredients – pycnogenol and arginine. I’ve been looking at pycnogenol for a while, but have seen some mixed data. This study says that the combination of these two substances helps men.

Now, you can buy these two ingredients separately, get higher doses, and save a lot of money. Worth a try? I don’t know. But the article appeared in International Journal of Impotence Research, which is presumably a decent journal.

UPDATE: I have been trying pycnogenol (50 mg, 3x day), with L-arginine, and I feel it has some slight benefit. This is subjective, of course, but it reminds me of the feeling I get from taking Horney Goat Weed – a sexual buzz. I have added it to my daily supplement list.

According to an article on the Internet, a good herb for men — which raises nitric oxide levels, important for healthy sexual behavior — is Cnidium. But I’d like to know what the medical literature says before I spend my hard-earned cash for this unknown herb.

So, I check www.PubMed – the National Library of Medicine – and search for Cnidium. There are a few studies – mostly from China, where they study herbs – which suggest benefits from cnidium.

Here is an abstract from one:

PURPOSE: We investigated the cavernosal relaxant effect of osthole, a coumarin isolated from Cnidium monnier (L.) Cusson which has been long used in China as a herbal medicine to improve male sexual dysfunction. MATERIALS AND METHODS: Strips of rabbit corpus cavernosum were precontracted with phenylephrine. Corporal relaxation evoked by osthole was then determined in the absence and presence of nitric oxide synthase inhibitor (L-NAME), soluble guanylate cyclase inhibitor (ODQ), cyclooxygenase inhibitor (indomethacin), tetradotoxin, and after endothelium deprivation. RESULTS: Corpus cavernosal strips showed relaxation in response to osthole (0.1 approximately 30 microM) in a dose-dependent manner. These effects were reduced partially but significantly by pretreatment with L-NAME, ODQ and by endothelial disruption. However, they were not affected by indomethacin and tetradotoxin treatment. Osthole pretreatment (from 1 to 30 microM) enhanced the sodium nitroprusside (0.3 microM)-induced relaxation of corpus cavernosum in a dose-dependent manner to a maximum of 3 times the pretreatment level at 30 microM osthole. However, this effect was abolished in the presence of zaprinast. Additionally, a higher concentration of osthole (30 microM) also enhanced forskolin-induced relaxation. CONCLUSION: The data suggested that osthole possesses a relaxant effect on rabbit corpus cavernosal tissues which is attributable to the release of NO from sinusoidal endothelium and to the potentiation of the cGMP and/or cAMP signal mediating relaxation of cavernosal smooth muscle by inhibiting phosphodiesterase.

Source (click on this link): J Urol. 2000 Jun;163(6):1975-80.

I just stumbled on some research that is worth investigating. There is a chemical called sialorphin that appears to play an important role in sexual behavior. The research below is especially interesting because it was conducted on aging rats.

More about sialophin at these links:

http://www.sciencedaily.com/releases/2009/09/090918181456.htm

http://www3.interscience.wiley.com/cgi-bin/fulltext/118508324/PDFSTART

Here is some recent research that shows combining yohimbine with sildenafil (Viagra) produces a better effect than taking Viagra alone.

The latest supplement I’ve tried is choline, an “organic compound” usually grouped as a B vitamin. Increasing choline use should increase levels of acetylcholine, a neurotransmitter involved in erections.

I have been starting with small doses (500 mg, 2x daily) but I feel like it may have some benefit, when I take it with pycnogenol, folic acid, vitamin C, and other supplements.

Here’s some links about using choline and the role of acetylcholine in erection: LINK, LINK, and LINK.

The Saudis, apparently, like to research herbs as alternatives to Viagra. Here is an abstract describing their experience with extracts from the plant Casimiroa edulis (I never heard of it, either). But if you are ever in Saudi Arabia, maybe you can score some. Let me know how it goes.

Here’s the link: (LINK HERE).

There is also information on IslamOnline.net (LINK HERE) about ED. They recommend various herbs, including Horny Goat Weed.

Please support my research, and send $1 to my Paypal account (menznews@yahoo.com).

Microdesmis keayana, an African plant used for ED by traditional medicine providers, has been shown to be associated with factors that raise nitric oxide levels (the same pathway that Viagra uses). Is it any good – or even available? I don’t know – first I’ve heard of it. For the study, CLICK HERE. Here’s another Africa herb that seems to relax blood vessels. CLICK HERE.

I’ve been hearing a bit about this herb – Montanoa tomentosa – which is from Mexico. I can’t tell you if it is any good but here is an article about it from a peer-reviewed journal (CLICK HERE). The investigators say that it appears to be helpful for making rats frisky.