Common side effects from alfalfa include upset stomach, diarrhea, and flatulence. Rarely, alfalfa may cause lupus-like effects (e.g., muscle pain, fatigue, skin rashes, fever, chest pain with deep breaths).
Alfalfa can interact with some medications. It decreases the effectiveness of some birth control pills. If you are taking alfalfa along with birth control pills, use an extra method of birth control, such as a condom. Alfalfa can also interact with warfarin, estrogen pills including hormone replacement therapy, medications that suppress the immune system (e.g., cyclosporine, corticosteroids), diabetes medications (e.g., metformin), iron, and vitamin E.
Alfalfa makes you more sensitive to sunlight, so you should avoid taking it while taking other medications that also make you sensitive to sunlight (e.g., amitriptyline, ciprofloxacin, tetracycline). In addition, cover up (wear sun block, long sleeves, and a hat) if you are taking alfalfa and are in the sun.
You should avoid alfalfa if you have a condition that is sensitive to hormones (e.g., breast cancer, endometriosis), if you have an autoimmune disease (e.g., multiple sclerosis, lupus, rheumatoid arthritis), or if you had a kidney transplant.
Women who are pregnant or breast-feeding should not use alfalfa. Consult your health care professional if you have any questions.
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.