Many here like Humaworm. It has many different herbs in it. It is only available directly from the manufacturer. It has small amounts of senna and buckthorn in it. These are laxative herbs. Some people are sensitive to these. I guess the laxative herbs are present in case someone has larger parasites, so they would be able to expel them easier. I have read that they make their formula in small batches and may even customize it for you, so you might be able to get it without the senna and buckthorn. Kroeger Wormwood Combination is a very poular and inexpensive choice. It come in bottles of 100 capsules for around $8 each. Two bottles would be needed for a one month cleanse. The Country Life Black Walnut wormwood liquid extract looks interesting. It is around $8 for a bottle. Up to 3 bottles may be needed for a one month cleanse. I have been wondering it liquid extracts or capsules are better for a parasite cleanse. I guess with liquid extracts the best idea may be to take them with a small amount of water 20 minutes after eating, so they mix well with the food in your stomach. With capsules, it might be a good idea to take them at the start of a meal. I guess someone could take half a dose of capsules and half a dose of extracts rather than just relying on one. Some formulas have quassia, or male fern, or other herbs. They all seem to have wormwood, black walnut green hull extract, and cloves.

PS. I just noticed that the Country Life Black Walnut Wormwood does not have cloves and does have buckthorn(cascara sagrada), so if one does get the Country Life formula, they should also get clove oil or capsules of ground cloves separately. The Now brand clove oil is good and very inexpensive, only around $6 for an ounce. Clove oil is toxic in larger quantities, so it should be taken 5 drops or less at a time mixed well in 2 ounces of water 3 times a day.

http://www.country-life.com/moreinfo.cfm?Category=4&Product_ID=42