Agent: Minoxidil

Minoxidil, as of 2018, was used to treat severe hypertension orally as a last-resort arterial vasodilator and topically for alopecia to promote hair growth, although its exact mechanisms were not fully understood. The medication, a prodrug, becomes bioactivated in the liver or hair follicles to its active form. Oral use carried a high risk of systemic toxicity, necessitating careful monitoring due to side effects like tachycardia and edema, and was contraindicated for patients with pheochromocytoma. Topical use needed to be continuous, as ceasing application would result in the loss of hair growth benefits. Minoxidil was deemed neither carcinogenic nor mutagenic in rodent studies.