Harm: it has a bad influence on sports; Side effects: causing muscle stiffness. Weight-reducing needles generally achieve their goal by injecting botulinum toxin to make the muscles of body parts smaller. Because the exercise system coordinates exercise by dominating muscles, injection of botulinum toxin is easy to make muscles atrophy, which has a bad influence on exercise; It is easy to cause local muscle stiffness, and even redness and pain at the injection site may occur.