L-arginine and L-citrulline are amino acids. Citrulline is a precursor to the synthesis of arginine. According to Mayo Clinic, the body changes arginine into nitric oxide, which helps blood vessels dilate, thus reducing blood pressure. By taking arginine and citrulline supplements, it may be possible for some people to lower their blood pressure. If you have hypertension, ask your healthcare provider if these two amino acids are appropriate for your condition.
Take 2 to 3 g of L-arginine, three times a day, suggests Mayo Clinic. There is not a standard recommended dose of this supplement, so check with your doctor to make sure this is an appropriate dosage. Nausea is a side effect that may occur; take this supplement with a meal or small snack to alleviate this.
Consume 3 g of L-citrulline twice a day. A 2009 study by A Figueroa, et al., published in the "American Journal of Hypertension," found that this dose of L-citrulline helped reduce blood pressure during a cold pressor test. L-citrulline is converted to L-arginine by the body, and lowers blood pressure by increasing nitric oxide production in the body.
Incorporate more foods rich in L-arginine and L-citrulline into your diet. Sources of arginine include walnuts, pecans, brown rice, raisins, coconut, chicken, chocolate, corn and meat. Citrulline food sources include meat, fish, eggs and legumes.