I just spoke with their nutrition department at the manufacturing plant in Bloomingdale, IL, and the arginine is derived from feathers and is thus NOT vegan. I am bummed as I had been using this product for some time now. Ajimoto/Ajipure pharmaceutical-grade amino acids are however vegan. Hope this helps someone.

Does this product conflict with Lisinopril?

Not sure but I did read something. I think it was on webmd.

What does free form L Arginine and L citrulline mean?

Free-form amino acids refer to single amino acids that are already in a pre-digested form and ready to be used by your body. Some nutritional products, especially amino acid blends, contain whole proteins and large peptides (chains of amino acids), which the body must first break down into smaller peptides and individual amino acids before use. For faster utilization and better bioavailability, look for free-form amino acids.

What is the prop 65 warning about ?

The California Prop 65 warning may inadvertently appear on the product page. This warning does not apply to this product and can be ignored, it is no longer live on this product page upon checking.