Trinity, the Raintree data base has excellent information about so many medicinal plants, including cat's claw.
Also, make sure you scroll down and read the contraindications and drug interactions. If the precise information you want is not on their website, e-mail them. They were helpful to me, long ago, when I first researched graviola.
https://www.rain-tree.com/catclaw.htm
Traditional Preparation: For general immune and prevention benefits, practitioners usually recommend 1 g daily of vine powder in tablets or capsules. Therapeutic dosages of cat's claw are reported to be as high as 20 g daily and average 2-3 grams two or three times daily. Generally, as a natural aid for arthritis and bowel and digestive problems 3-5 g daily is recommended, if a good product is obtained. Alternatively, a standard vine bark decoction can be used much the same way indigenous people of the Amazon use it. The dosage for a standard decoction for general health and maintenance is 1/2-1 cup of a decoction once daily and up to 1 cup three times daily in times of special needs. Adding lemon juice or vinegar to the decoction when boiling will help extract more alkaloids and fewer tannins from the bark. Use about 1/2 teaspoon of lemon juice or vinegar per cup of water. For standardized and/or proprietary extract products, follow the label instructions.