What was Botox first approved by the FDA for?

Botox was initially approved by the FDA for the treatment of crossed eyes (strabismus) and twitching eyelids (blepharospasm). This approval was granted because Botox acts as a neuromuscular blocker; it temporarily paralyzes the muscles around the eyes, which helps alleviate the symptoms associated with these conditions. The use of Botox in this context demonstrated the effectiveness of the toxin in managing muscle-related disorders, establishing its initial therapeutic role.

Subsequent FDA approvals followed for other uses such as treating chronic migraines, excessive sweating, and cosmetic applications for facial wrinkles. However, those uses came later as the understanding of Botox's capabilities expanded.