Amazon has the 100-Count Puritan's Pride L-arginine 1000 Mg Capsules (4332490165) for $8.18 - 15% off coupon (check “Save an extra” box, eligible on first S&S order for this product) - 5% off with Subscribe & Save (can cancel anytime) = $6.54 with free shipping on $35+ or with Prime (extra 15% off for 5+ subscribe and save orders).

Arginine is one of 20 amino acids, the building blocks of protein.