Hi, Thank you for your query. I can understand your concerns. Omni Drops are pharmaceutical quality HCG, made in an FDA-approved lab. They contain HCG and vitamin B-12. The most common side effects experienced by people taking HCG drops for weight loss actually stem from the accompanying diet. However side effects may include: Headache. Some people experience minor headaches during the first week of the low-calorie diet. Mild dizziness. Mild dizziness is not uncommon, but it usually goes away after the first week. Constipation. On a low-calorie diet, it s normal for bowel movements to come less often, sometimes just once every 3 or 4 days. Rash (rare). As your body consumes fat, normal toxins are released into your body. Because of the breakneck speeds at which your body consumes fat on the HCG diet, these toxins can build up and cause a minor rash. Leg cramps (rare). Cramps may occur due to the lack of potassium in the Core Phase diet. Potassium supplements can be used to treat this symptom. These side effects only affect a small percentage of individuals taking omni drops(HCG drops) and are typically very mild. However, if you experience any symptom that concerns you or a serious headache that lasts longer than 10 days, you should consult with your doctor. Regards Dr. T.K. Biswas M.D. Mumbai