15-keto Latanoprost is a potential metabolite of latanoprost when administered to animals and is a common minor impurity in commercial preparations of the bulk drug compound. Although much less potent than latanoprost, 15-keto Latanoprost can still produce a small but measurable decrease (1 mm Hg) in intraocular pressure in normal cynomolgus monkeys at a dose of 1 μg/eye. It also acts as a miotic in normal cats, causing an 8 mm Hg reduction in pupillary diameter at 5 μg/eye, though it is not as potent as many other F-type prostaglandins, such as prostaglandin F2α, which achieves the same effect at less than 1 μg/eye.