A poster on the Peak Testosterone Forum wrote in and asked if citrulline would increase the salivary nitrite levels that the new Berkeley Test Strips measure:
“Can someone tell me what is the appropiate dose of Citrulline and if I should see any change in my Berkley strips ? I’m not seeing any increase in my measurements. I’m taking 2 (1.2 grams) tablets of L Citrulline from Now Foods each day divided in two servings . I’m not seeing any increase in my measurements. Thanks in advance.” 
Of course, this same question would also likely apply to arginine as well, because citrulline essentially is an alternate way to increase arginine levels. For more information, see my link on The Benefits of Citrulline. And I answered the poster that I knew citrulline and arginine can increase endothelial nitric oxide levels, but that that would not necessarily translate into increased salivary nitrite levels.
CAUTION: Arginine should be used with care and I explain some of the risks in this page on Herpes and Arginine
To find out if I was right, I wrote the good people at Berkeley Test. There are so many scammers in the health business, but all my interactions with this company have been excellent: they are helpful, knowledgeable and emphasize whole plant foods to boost nitric oxide. You can read a very interesting interview that I had with them in my page on A Review of Berkeley Test Strips for more information, where they document how the Berkeley Test Strips actually measure salivary nitrite levels. This is a back door method that your body has to increase arterial nitric oxide levels and is VERY important for any man over about the age of 35 to place in his bedroom arsenal. Again, read the above link and you’ll understand how it works.
Berkeley’s response was very interesting and essentially verified what I said, i.e. that some key things can upgrade and downgrade the production of your regular, arterial nitric oxide levels:
“Keep in mind, arginine is a semi-essential amino acid, so a balanced diet provides a source. However, a supplemental Citrulline / Arginine blend can augment NO bioavailability. However, there are a number of factors that can influence the outcomes, such as:
1. Expression of NOS, which can be influenced by exercise (high intensity and daily routines can up regulate its expression) and age (as we age or become more sedentary, NOS expression is lower),
2. The presence of arginase (which breaks down arginine, thereby reducing the availability for NOS usage) and
In other words, citrulline and arginine may not improve nitite levels, but they can boost arterial NO levels of course along with exercise. And, generously as always, they even went to give some ideas on ways to actually increase your salivary nitrite levels directly:
“We have been told products such as nitroxyl or arginext with B12 to be effective at enhancing saliva NO levels in individuals with healthy BMI and daily exercise.
The individuals also incorporate multiple leafy green salads into their diet and, on occasion when salads are not available, they will supplement with Peak Nitric Oxide or various beet juices, such as Red Ace, Red Rush, or Beet It — these 3 our the most potent and have been well characterized for contributing the the alternative or non-NOS pathway. And the supplement, Peak Nitric Oxide, is based on the NO3 concentration of a Beet It shot, which can be equally effective and its duration is longer in comparison to Neo40, which we have been told to be short-lived and too expensive.
So, a natural whole food diet with the incorporation of multiple leafy green salads per day with a beet shot and the additional of a citrulline source, when necessary of arginext (arginine/citrulline)/b12 or nitroxyl/B12 with daily exercise, and, if necessary, Peak Nitric Oxide as a supplement can be an effective way to sustain your NO levels as validated by Berkeley Test. Keep healthy and eat smart.”
The safey of nitroxyl and arginext I do not know: you’ll have to do your own research. But the bottom line is that citrulline (and arginine) can increase endothelial nitric oxide and can be used synergistically with a few supplements, higher nitrate foods and nitrate-food-based supplements.