Sustained + Immediate Release L-Arginine

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Give yourself a boost! Experience the effects of both immediate and sustained released amino acid L-Arginine for athletic endurance and performance. read more

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Product overview

Doctor’s Best Sustained + Immediate Release L-Arginine provides a unique 2-in-1 formulation that provides an immediate boost of L-Arginine for use, as well as a sustained delivery over an 8-hour period to maintain peak levels in circulation throughout the day. L-Arginine is best known as a precursor of nitric oxide (NO) which increases vascular dilation with enhanced oxygenation of blood flow for athletic endurance and cardiovascular health.   

  • 2-in-1 formula for enhanced L-Arginine levels in circulation for cellular use over the course of the day
  • Helps boost nitric oxide (NO) levels to support improved vascular dilation and oxygenation for normal blood pressure balance and circulatory health, and enhanced athletic performance
  • Offers support for the respiratory and nervous systems, as well as sexual function
The importance of sustained release

Most supplemental L-Arginine formulations are quickly absorbed into the bloodstream, and just as quickly broken down resulting in a short-lived burst of L-Arginine in circulation for use. This requires large doses to be consumed more frequently throughout the day to produce an effect. With the benefit of both an immediate burst and the maintenance of arginine in circulation continuously over an 8-hour period, Doctor’s Best Sustained + Immediate Release L-Arginine outperforms other supplemental forms for greater performance, for longer.

How does it work?

L-arginine is required to synthesise nitric oxide in the human body. Nitric oxide is a powerful neurotransmitter that helps blood vessels relax, thereby supporting circulation and improving the oxygenation of blood flow. Because L-arginine acts as a vasodilator, opening (dilating) blood vessels, many people take oral L-arginine to support heart conditions, erectile dysfunction, mental acuity and overall circulation. This becomes increasingly important with advancing age, as natural nitric oxide production falls.  Studies indicate that at 40 years of age, an individual is likely making less than half the amount of nitric oxide they were at the age of 20.

The use of L-arginine during exercise supports anaerobic and ventilatory thresholds, which supports a decrease in oxygen cost during exercise and extended time to exhaustion. Research suggests that L-arginine supplementation may play a beneficial role on athletic performance by supporting muscle protein synthesis.  Arginine-derived nitric oxide has been shown to help support muscle mass, muscle growth, and endurance, as it’s a precursor to creatine, which supplies energy to cells.

About Doctor’s Best

Doctor’s Best creates vitamins and supplements using science-based techniques, that combine natural ingredients using thoroughly researched and tested methods. Doctor’s Best is committed to transparency and education, and uses only certified cGMP facilities to ensure the highest quality standards are met.


L-Arginine (as 500 mg immediate release and 500 mg sustained release from L-Arginine Alpha-Ketoglutarate) 1,000 mg. Other ingredients: Microcrystalline cellulose, stearic acid, silicon dioxide, magnesium stearate (vegetable source), croscarmellose sodium, hypromellose (coating).

Does not contain: GMO, Gluten, Soy. 100% vegan.

Suggested Use

Recommended intake:

Suggested Adult Use: Take 2 tablets daily with food, or as recommended by a health practitioner.

  • Not intended for individuals under the age of 18.
  • If pregnant, nursing, have a medical condition or taking medications, nitrates, warfarin, sildenafil (Viagra), blood pressure lowering medications or supplements, consult a healthcare practitioner prior to use.
  • Do not use if safety seal is broken or missing.
  • Keep out of reach of children.
  • Always read the label and use as directed. If symptoms persist see your healthcare practitioner.


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