Hi dear, There is very little medial literature available for herbalife. The formula contains protein, fiber, vitamins, minerals etc. Omega 3 is also nutritional supplement. However, your trouble is with delayed menstruation, which is a hormonal phenmenon. I can tell that the nutritional supplements you are taking do not have any adverse effects on periods. You may have other reason for the trouble, like pregnancy, presence of ovarian pathology etc. To rule out pregnancy, you can take home pregnancy test that is available over the counter. If you are not pregnant, do consult a gynecologist to find the reason of absent periods and to get medicines for that. Herbalife do help in losing weight very fast. But again, there is not much medical evidence available to tell you surely if using it regularly has any side effects. I hope this information helps. Thank you for choosing HealthCareMagic. Stay healthy! Best, Dr. Viraj Shah