Also known as creatine hydrochloride, creatine HCI is thought to be a more soluble alternative to creatine monohydrate. Like other forms of the molecule, creatine HCI is said to help users increase energy, strength and endurance, while also improving athletic performance. But while it is thought to have offer the same benefits as other forms of the nutrient, creatine HCI is more acidic than monohydrate, which (in theory) makes it more soluble and therefore more readily absorbed by the body. Some brands state this could help some users avoid stomach cramps they experience when using creatine monohydrate. In most cases, creatine HCI is more expensive than creatine monohydrate.