The best discount code for primalherb.com currently available is FIRSTBUY10, which provides a 10% discount on your next order. This code is especially beneficial for first-time buyers. Additionally, there are other promotions such as free shipping on orders $45 or more, and an additional 5% discount when you add any 4 products to your cart. Please note that these codes and promotions may vary and it's always a good idea to check the official PrimalHerb website or other coupon sites for the latest deals.