Bio-identical hormones are chemically the same as the hormones we produce in our bodies. It is thought that the bio-identical hormones act more naturally in our bodies than synthetic hormones such as Premarin, which is made from pregnant horse urine. However, bio-identical hormones have not been studied by the FDA so should be used under the care of a physician and you should have your hormone levels checked regularly. Bio-identical testosterone, progesterone, and estrogen are derived from wild yams. You cannot get the hormones by simply eating yams; they must be extracted. The hormones are available in drops, pills and creams, however I usually recommend drops because the dosage can be adjusted more easily. I do not recommend the creams because the hormones can rub off onto your husband, children and even pets.