L- Arginine is a conditionally essential amino acid. It is one of the three amino acids that are part of the urea cycle alongside L ornithine and L citrulline.
It is a Nitric Oxide precursor and gets converted to Nitric Oxide through the endothelium Nitric Oxide Synthase enzyme.
The endothelium is a smooth lining of the veins, arteries, and internal organs of the body, like the heart, kidneys, and liver.
In the Veins and arteries, the endothelium dilates and opens more allowing for greater blood flow around the whole body, including the genitalia parts.
The L-Arginine dosage depends on what condition is being treated, or what health benefit it is being taken for.
This supplement is often taken to improve cardiovascular health and may be recommended by your doctor for congestive heart failure and chest pain (Angina pectoris) treatment.
L-Arginine supplements are used to help heal wounds faster, improve healing of bone fractures, promote shorter recovery times for athletes and weightlifters, and also taken to improve exercise performance and to help erectile dysfunction.
It is also used to treat malnutrition and to enhance the functioning of the immune system.
L-Citrulline is another supplementation option that is converted into arginine in the kidneys.
It also has a better absorption rate and is able to increase levels of plasma arginine that is more effective than arginine itself.
Effects of L-Arginine
Arginine has been implicated in reducing blood pressure, however, the degree of reduction does not appear to be too remarkable and it is unreliable in doing so.
It may also increase blood flow secondary to activating nitric oxide.
Also, due to the unreliability of increasing nitric oxide, there is also unreliability in how arginine increases blood flow.
When nitric oxide is increased, the oxygenation cost of exercise or work-outs appears to be decreased.
Arginine has been implicated in increasing growth hormone (at rest) and suppressing an exercise-induced increase in growth hormone.
In persons with impaired glucose tolerance, an increase in adiponectin (and the adiponectin: leptin ratio) has been noted with supplemental L-arginine, and no significant influence on heart rate has been seen with supplemental L-Arginine.
Furthermore, in persons with impaired glucose tolerance or type II diabetes, L-arginine appears to have an indirect antioxidant role and increases superoxide dismutase concentrations.
A slight reduction in fat mass has been noted with long-term usage in persons with impaired glucose tolerance, however, no evidence supports the use of arginine as a fat burner in otherwise healthy persons.
L-Arginine Dosage Guidelines
The standard pre-workout dose for L-arginine is 3-6g, and to maintain elevated arginine levels throughout the day, it can be taken up to three times a day, with a combined dose total of 15-18g.
Thus, the dosages of the L-Arginine range between 3 g to 18 g per day, with most users taking between 5 – 10 g on a regular basis.
Dosages are typically split up into 2 or 3 administrations per day to ensure a consistent supply of the amino acid all day long.
For improving athletic performance the suggested amount is 4 to 5 g of L-arginine approximately 60 minutes before working out, in order to increase energy levels and promotes overall endurance for athletic events.
For erectile dysfunction, depending on the severity of erectile dysfunction 4,000mg to 6,000mg is the ideal recommended dosage.
Best taken spread evenly throughout the day at intervals of 8 hours.
Note that taking more than 10g of arginine at once can result in gastrointestinal distress and diarrhea, and L-Citrulline supplementation is believed to be more effective at maintaining elevated arginine levels for long periods of time.
Who Should Not Take L-Arginine?
L-arginine should not be taken right after a heart attack. In a study where 9 grams of L-arginine was given daily for 3 to 21 days after a heart attack, it resulted in an increased mortality rate.
People with kidney or liver disease should consult their doctor before taking L-arginine supplements, and there have been few case reports of severe allergic reactions following intravenous administration of L-arginine.
L-arginine should not be used by persons suffering from a herpes virus condition because it might help the replication of the virus.
Some side effects reported include:
- Airway inflammation,
- Allergies,
- Bloating,
- Blood abnormalities,
- Diarrhea,
- Gout,
- A headache and
- Low blood pressure.
These side effects may be aggravated when taking L-Arginine dosages in excess of 10 grams per day, and it may also cause Asthma symptoms to become worse.
When taking L-arginine supplementation, medications that increase blood flow to the heart (Nitrates) should be avoided, as well as antihypertensive drugs.
Viagra lowers blood pressure and may cause the blood pressure to be too low when taken with this supplement.
Safety
L-arginine supplement usage should be discontinued two weeks before scheduled surgery and should be used with caution by pregnant or breastfeeding women.
The observed safety limit, in which one can be relatively assured that no side effects will occur over a lifetime, has been suggested as being 20g of arginine a day in supplemental form.
Higher doses have been tested and well-tolerated, but no proof exists to suggest their safety across a lifetime, in all populations.