The pH level of lemon juice is about 2.0. Anything below 7 for pH levels means that it is an acid. Lemon juice is a strong acid. Lemons are strong in acidity because they are made of citrus juice and ascorbic acid.
The pH level of water is 7, which is considered neutral. Drinking acidic lemon juice as a part of your diet may help with digestion and weight loss. Further, drinking warm lemon juice mixed with water can help cleanse the body of harmful toxins. Lemon juice has also been shown in studies to have properties that protect against cancer.