This is probably because it contains plant compounds called saponins. There is a long list of traditional uses of alfalfa as a medicinal herb. They include lowering blood pressure, acting as a diuretic, increasing breast milk production, treating arthritis, and getting rid of kidney stones.

Alfalfa is an herb. People use the leaves, sprouts, and seeds to make medicine. Alfalfa is used for kidney conditions, bladder and prostate conditions, and to increase urine flow. It is also used for high cholesterol, asthma, osteoarthritis, rheumatoid arthritis, diabetes, upset stomach, and a bleeding disorder called thrombocytopenic purpura.