As a natural way to lose weight, herbal tea should have no side effects in theory. However, different people have different tolerance to the ingredients of white grass tea, and the following adverse reactions may occur:

1. Gastrointestinal discomfort: including diarrhea, abdominal pain, nausea and vomiting.

2. Allergic reaction: Some people may be allergic to the plant ingredients in white grass tea, and have symptoms such as rash, itching and dyspnea.

3. Drug interaction: Some components in white grass tea may interact with other drugs, affecting drug efficacy or increasing adverse reactions.

Therefore, if you plan to use herbal tea to lose weight, you'd better consult a doctor or a professional before using it to ensure your safety and health.