Hello and thank you for asking! I have gone carefully through your concern. The treatment recommended by your physician to treat over active thyroid is the right one. The are some side effects of neomarcazole that you should be aware of: Gastrointestinal upset, nausea, headache, arthralgia (painful joints), skin rash, itching (pruritus), loss of taste. Agranulocytosis (reduced white cell count) is a possible serious side effect that should be monitored for symptoms like sore throat, bruising, bleeding, mouth ulcers, fever and malaise. In these cases stop the treatment immediately and inform your physician. There is no need to follow an appropriate diet. Once the hormonal level is back to normal, you will get back to the previous weight. For a personalised comprehensive evaluation, treatment recommendations, or individual therapy, ask me at HealthCareMagic at this private link: HCM Dr. Guni Best wishes, Dr.Mirjeta