Freebase nicotine is the purest form of nicotine used in e-liquids. It is created by adding ammonia to nicotine extracts, which increases the pH level and leads to deprotonation of the nicotine molecules. This process makes the nicotine more bioavailable, meaning it is more readily absorbed by the lungs and crosses the blood-brain barrier more efficiently. Freebase nicotine is known for providing a stronger throat hit compared to nicotine salts and is commonly used in vaping products designed for smokers looking to transition to vaping. It is typically found in lower concentration e-liquids used with higher-powered vaping devices.