I made some homemade tonic using lime and lemon peel. I brought to boil and simmered for 2 hrs. Never take off the pot cover. Let it cool overnight.
Next day I strained and decanted into a nice bottle and put it in the fridge. I've been taking a couple teaspoons in my favorite juice - i.e. orange or pineapple - and I've been feeling a little more energetic lately. Try just making your own, it's not hard. There are videos on it too and there are other flavors and ingredients you can use, most used grapefruit, but I couldn't find any organic.