Add 1 cup of water in a saucepan and heat up a little without letting it boil.
Meanwhile, squeeze a lemon and reserve its juice.
When the water is hot add the lemon juice, mix well with the help of a wooden spoon and serve in a glass or cup.
You should take this natural beverage on an empty stomach. You have to take it right when you get up in the morning, first thing in the morning and without having drunk anything else. It is not advisable to take it hot, but wait a little to be warmer.