According to Dr Saniyya Mahmood, medical director of Aesthetica Medical Clinic in Leeds, "infection, cysts, brow and eyelid droop, muscle weakness and asymmetry" are some of the more serious side-effects of Botox. She added: "It is therefore imperative to ensure you only see an experienced, medical practitioner for treatments to reduce the risk of side effects. "Botulinum toxin is a very effective treatment both cosmetically and medically if done in the right candidate and for the correct indication. "It is a fairly safe procedure when administered in experienced hands. If you experience any side effects, always consult your medical practitioner for advice. "