No, it is not a progestin. Btw. progestin is always synthetic and used in birth control pills or HRT medicines. Walnut leaves contain natural progesterone. It was discovered only recently (2010).
Leaves of the Common Walnut = Juglans regia (also called English Walnut), tree should not be confused with BLACK walnut = Juglans nigra hulls (antiparasitic), you are referring to! Black walnut is widely available in the US, but it is NOT the same like juglans regia which contains progesterone.
http://www.sciencedaily.com/releases/201...144815.htm
PS: Juglans regia is also used to treat cancer.
Leaves of the Common Walnut = Juglans regia (also called English Walnut), tree should not be confused with BLACK walnut = Juglans nigra hulls (antiparasitic), you are referring to! Black walnut is widely available in the US, but it is NOT the same like juglans regia which contains progesterone.
http://www.sciencedaily.com/releases/201...144815.htm
PS: Juglans regia is also used to treat cancer.