Nitric oxide is a molecule that plays a crucial role in vascular disease. Nitric oxide has a number of actions that lead to relaxation of blood vessels, regeneration of the endothelium (the inner lining of arteries), and inhibition of platelet clumping which makes the blood thinner. The role of nitric oxide in vascular disease has been investigated over the past two decades and scientists have discovered that this molecule is involved in many cardiovascular diseases, including atherosclerosis and thickening of the endothelium. In addition, nitric oxide has been used as a therapeutic tool to treat diseases that range from recurrent narrowing of arteries to inhibiting clotting events. Many commonly used medications have their therapeutic actions through the production of nitric oxide.

Impotence and nitric oxide
One of the main physiological causes of impotence, or erectile dysfunction, is inability of the blood vessels in the penis to dilate enough to allow blood flow and engorgement. The most important chemical involved in this process is nitric oxide. Arginine, an amino acid available as a supplement, can help make more nitric oxide but the doses required are high and the effects may not last for long. Fortunately, there are several herbal supplements that can help dilate blood vessels, including ginseng and others less known but more powerful. Passion Rx has a combination of several potent herbal extracts that help dilate blood vessels and improve erectile function, along with libido and sensation.

More Nitric Oxide chemistry
Nitric oxide is formed from the conversion of L-arginine by an enzyme called nitric oxide synthase. Nitric oxide can act on neurons in the penis casuing dilation of the corpus cavernosum. Nitric oxide is released from nerve endings and endothelial cells and stimulates the activity of guanylate cyclase, leading to an increase in cyclic guanosine-3',5'-monophosphate (cGMP) and, finally, to cavernous smooth muscle relaxation.

Nitric Oxide Supplement
There are products that claim to be nitric oxide supplements, but I can't see how nitric oxide, a fleeting neurotransmitter, can be made into a supplement. However, if the supplement includes arginine that converts into nitric oxide, that's different. Or the supplement may have certain nutrients or herbs that make it more likely for the body to make nitric oxide or to keep the nitric oxide levels higher once they are made. It would not be accurate to claim a product is a nitric oxide supplement, but it could be accurate to make the claim that substances within the product could enhance nitric oxide production.

Nitric Oxide side effects
One theoretical potential of very high levels of nitric oxide is low blood pressure.

Nitric Oxide Research Update
Effects of soy germ isoflavones and hormone therapy on nitric oxide derivatives, low-density lipoprotein oxidation, and vascular reactivity in hypercholesterolemic postmenopausal women.
Menopause. 2006 Oct 2; From the 1School of Pharmaceutical Sciences, University of Sao Paulo, Sao Paulo, Brazil; 2Dante Pazzanese Institute of Cardiology, Sao Paulo, Brazil; and 3InCor Heart Institute, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil.
To evaluate the effects of soy germ isoflavones and hormone therapy on vascular reactivity, the formation of nitric oxide derivatives, and lipid peroxidation in hypercholesterolemic postmenopausal women. Women were treated with soy germ, 17beta-estradiol or 17beta-estradiol + noretisterone acetate for 3 months after taking placebo for 1 month. The plasma concentrations of nitrite + nitrate and S-nitrosothiols were evaluated by gaseous phase chemiluminescence; nitrotyrosine, electronegative low-density lipoprotein, and estradiol levels were determined by enzyme-linked immunosorbent assay; cholesterol oxides and isoflavones were determined by gas chromatography and high-performance liquid chromatography, respectively. Results: Soy germ isoflavones and hormone therapy induced a decrease in nitrite + nitrate, electronegative low-density lipoprotein, and cholesterol oxides, as well as an increase in S-nitrosothiols. Soy germ isoflavones lowered electronegative low-density lipoprotein, and cholesterol oxides more efficiently than did hormone therapy. Only soy isoflavones inhibited nitrotyrosine formation. A significant improvement of vascular reactivity was only seen in women treated with 17beta-estradiol. Conclusions: The soy germ isoflavones and 17beta-estradiol, alone or associated with noretisterone acetate, in the doses and forms used here, have similar effects on the bioavailability of nitric oxide. Soy germ treatment inhibited lipid peroxidation more effectively than hormone therapy.

Acute consumption of flavanol-rich cocoa and the reversal of endothelial dysfunction in smokers.
J Am Coll Cardiol. 2005 Oct 4;46(7):1276-83.
This study was designed to assess the effect of flavanol-rich food on the circulating pool of bioactive nitric oxide and endothelial dysfunction in smokers. Studies suggest that smoking-related vascular disease is caused by impaired nitric oxide synthesis and that diets rich in flavanols can increase bioactive nitric oxide in plasma. CONCLUSIONS: The circulating pool of bioactive nitric oxide and endothelium-dependent vasodilation is acutely increased in smokers following the oral ingestion of a flavanol-rich cocoa drink. The increase in circulating nitric oxide pool may contribute to beneficial vascular health effects of flavanol-rich food.

Cardiovascular effects of the phytoestrogen genistein.
Curr Med Chem Cardiovasc Hematol Agents. 2004 Apr;2(2):179-86.
Phytoestrogenic molecules have received a great deal of attention over the last few years because of their potentially preventive roles against a few of today's most prevalent chronic diseases, namely cardiovascular diseases, osteoporosis and hormone related cancers. Of the several phytoestrogens, genistein in particular has been shown to be the most efficacious in animal models and experimental studies. Genistein in vitro relaxes rat arteries by a nitric oxide dependent mechanism and enhances the dilator response to acetylcholine of atherosclerotic arteries. Genistein supplementation improves endothelial dysfunction induced by oophorectomy in rats and reduces infarct size in an experimental model of myocardial ischaemia-reperfusion injury. Furthermore, genistein in postmenopausal women increases plasma nitric oxide breakdown products, reduces endothelin-1 levels and improves endothelial dependent vasodilation in post-menopausal women. All these findings, taken together, would suggest that this molecule might represent an attractive alternative for cardiovascular protection.

Acetylcholine -induced vasodilation is mediated by nitric oxide and prostaglandins in human skin.
J Appl Physiol. 2005 Feb;98(2):629-32.
Acetylcholine can effect vasodilation by several mechanisms, including activation of endothelial nitric oxide synthase and prostaglandin (PG) production. In human skin, exogenous acetylcholine increases both skin blood flow (SkBF) and bioavailable nitric oxide levels, but the relative increase is much greater in SkBF than nitric oxide. This led us to speculate acetylcholine may dilate cutaneous blood vessels through PGs, as well as nitric oxide. To test this hypothesis, we performed a study in 11 healthy people. We measured SkBF by laser-Doppler flowmetry (LDF) at four skin sites instrumented for intradermal microdialysis. We conclude that a portion of the vasodilation effected by exogenous acetylcholine in skin is due to nitric oxide; however, a significant portion is also mediated by PGs.

Nitric oxide, human diseases and the herbal products that affect the nitric oxide signalling pathway.
Clin Exp Pharmacol Physiol. 2003 Sep;30(9):605-15.
1. Nitric oxide is formed enzymatically from l-arginine in the presence of nitric oxide synthase. Nitric oxide is generated constitutively in endothelial cells via sheer stress and blood-borne substances. Nitric oxide is also generated constitutively in neuronal cells and serves as a neurotransmitter and neuromodulator in non-adrenergic, non-cholinergic nerve endings. Furthermore, Nitric oxide can also be formed via enzyme induction in many tissues in the presence of cytokines. 2. The ubiquitous presence of nitric oxide in the living body suggests that nitric oxide plays an important role in the maintenance of health. Being a free radical with vasodilatory properties, nitric oxide exerts dual effects on tissues and cells in various biological systems. At low concentrations, nitric oxide can dilate the blood vessels and improve the circulation, but at high concentrations it can cause circulatory shock and induce cell death. Thus, diseases can arise in the presence of the extreme ends of the physiological concentrations of nitric oxide. 3. The nitric oxide signalling pathway has, in recent years, become a target for new drug development. The high level of flavonoids, catechins, tannins and other polyphenolic compounds present in vegetables, fruits, soy, tea and even red wine (from grapes) is believed to contribute to their beneficial health effects. Some of these compounds induce nitric oxide formation from the endothelial cells to improve circulation and some suppress the induction of inducible nitric oxide synthase in inflammation and infection. 4. Many botanical medicinal herbs and drugs derived from these herbs have been shown to have effects on the nitric oxide signalling pathway. For example, the saponins from ginseng, ginsenosides, have been shown to relax blood vessels (probably contributing to the antifatigue and blood pressure-lowering effects of ginseng) and corpus cavernosum (thus, for the treatment of men suffering from erectile dysfunction; however, the legendary aphrodisiac effect of ginseng may be an overstatement). Many plant extracts or purified drugs derived from Chinese medicinal herbs with proposed actions on nitric oxide pathways are also reviewed.

Nitric oxide helps patients with SARS
For patients with severe acute respiratory syndrome (SARS), inhaling nitric oxide leads to improved oxygenation and less need for mechanical ventilation, according to a new report. Nitric oxide or NO (not to be confused with nitrous oxide "laughing gas, NO2) has dilating properties, and is sometimes used to help babies with breathing problems, for example.

Although nitric oxide can halve the risk of developmental problems in premature babies with undeveloped lungs, the gas could be harmful to newborns who are too small and too ill. Doctors should avoid using nitric oxide treatment during the first week of life in premature babies who are seriously ill and weigh less than 1,000 grams (2.2 pounds). Short-term use of inhaled nitric oxide cannot be considered an effective rescue therapy for very preterm infants with profound respiratory failure.

Nitric Oxide for Premature Babies
Infants born prematurely are at increased risk for a chronic lung disease, called bronchopulmonary dysplasia, associated with prolonged use of oxygen therapy or a respirator. Adding nitric oxide (NO) to the air they breathe can reduce that risk in some infants, and may also improve other outcomes.

Herbs that help produce or enhance nitric oxide
There are countless herbs and herbal extracts that can help make more nitric oxide or stimulate nitric oxide release within endothelial cells. I have just listed a few and will add more with time.
Apocynum substance
Chrysin herb
Cacao has polyphenols
Ginseng is used for energy and sexual enhancement

Nitric oxide may be called a hormone

Nitric oxide and blood transfusions
Much of the stored blood given to millions of people every year may lack nitric oxide which is vital to delivering oxygen to body tissues. Nitric oxide helps keep blood vessels open. However, it begins breaking down as soon as blood goes into storage. Unfortunately, oxygen cannot get to the tissues that need it without nitric oxide,

Nitric oxide questions
Q. I am a bodybuilder that has been taking the supplement Nitric Oxide to help gain muscle mass. I also have a erectile dysfunction. I like to know if Viagra and the supplement Nitric Oxide can be taken together, and what side effect are.
   A. There is no such thing as far as we know of nitric oxide itself in the form of a supplement since nitric oxide is a gas, and many companies have a ' nitric oxide ' supplement product and each one of them has a different composition or ingredients. Many of these ' nitric oxide supplement ' products have arginine. Therefore, we really don't know what you mean by ' the supplement Nitric Oxide. '

Q. I saw you website and thought you may be able to direct me to information re: nitric oxide side effects. My brother was recently taking NO2 from GNC, he has had a severe reaction and was hospitalized due to psychosis. He has no prior history of any type of psychiatric disorder. Is there any research regarding psychiatric side effects of nitric oxide supplement?
   A. There are various products out there that claim to increase nitric oxide levels. A product that is called Nitric Oxide does not necessarily mean it has nitric oxide in it since NO is a gas that cannot be taken as a supplement. Some herbs and nutrients may increase the body's production of nitric oxide. As far as NO2 from GNC, we took a look at the product on the internet, It appears that there is a product NO2 from MRI, it says, :NO2 Black represents a quantum leap in nitric oxide science. First, NO2 Black sets the standard by giving you the purest Arginine-AKG (ArginPure) Delivered with its clinically tested extended-release delivery technology, pHylex9. Second, NO2 Black's revolutionary "NOS-Enhancing" peptide fraction up-regulates nitric oxide synthase (NOS) and increases your nitric oxide levels as much as 950% over baseline arginine derived nitric oxide (ADNO). Third, the NO2 Black formula includes alpha-lipoic acid, designed to boost your insulin sensitivity and nutrient uptake. Simply put, NO2 Black is the most potent nitric oxide generator ever conceived.*
   We have not seen any studies that have evaluated NO2 levels in humans when given this NO2 product. You may wish to ask the manufacturer what studies have been done and published in a reliable medical journal, and also what side effects have been reported.

Q. Though I test in the normal range of testosterone, I have trouble with erections when I need them and am wondering if there is a blood test to determine the level of nitric oxide in a person's system and whether I am in the normal range? Though you mentioned that l-citrulline is not good for getting erections, would it safely increase the level of nitric oxide in my system so when I need to have an erection I will have enough nitric oxide in my system to help me?
   A. Nitric oxide is a transient substance in the bloodstream and there are no easy tests in a doctor's office to determine levels of nitric oxide. A blood test for nitric oxide at one specific time would mean nothing since levels can fluctuate tremendously throughout the day. Citrulline or arginine may raise nitric oxide levels, but their effect is transient. Rather than focusing on nitric oxide levels, consider trying any of a number of sexual enhancing herbs or supplements that work in multiple ways to improve erections.