Sumatriptan 100 mg is a medicine used to treat cluster headaches and migraines. It belongs to the triptan class of drugs, which are also known as 5-HT1 serotonin agonists.

Cluster headaches affect one eye at a time, causing discomfort and swelling. They are more frequent in males than in women, and they may begin at any age. Cluster headaches are always terrible, although they only last 15 minutes to an hour at most.