Intravenous immunoglobulin (IVIG) is scientifically validated as an effective treatment for Myasthenia Gravis (MG), particularly in cases of acute exacerbations or myasthenic crises. MG is an autoimmune disorder in which antibodies target the acetylcholine receptors at the neuromuscular junction, impairing muscle contraction. IVIG, a concentrated preparation of antibodies derived from pooled human plasma, is thought to work by modulating the immune response. The exact mechanism is not fully understood but may involve neutralization of pathogenic autoantibodies, inhibition of complement activation, and interference with antibody production.

Multiple randomized controlled trials and meta-analyses have demonstrated that IVIG can rapidly improve muscle strength and reduce symptoms in patients with MG. It is often considered as an alternative to plasma exchange, especially when rapid clinical improvement is required or when plasma exchange is unavailable or contraindicated. Guidelines from neurological associations, including the American Academy of Neurology, recommend IVIG as a standard therapy for MG in specific scenarios.

IVIG is not typically used as a long-term maintenance therapy but is a critical component in the management of severe or refractory cases and in preparation for surgery (such as thymectomy) in MG patients. Its safety profile is generally favorable, though side effects can include headache, infusion reactions, and, rarely, thromboembolic events.