Oxyfluorfen

Selective, Broad spectrum pre- and postemergent herbicide. It targets a specific enzyme Protoporphyrinogen oxidaze in the chlorophyll biosynthetic pathway which leads to cell membrane integrity and plant death.

Oxyfluorfen isn't actually a medical substance. It's an herbicide, a weed killer [US EPA - Pesticides - Fact Sheet for Oxyfluorfen].

Here's what oxyfluorfen is used for:

• Controlling weeds: It targets both broadleaf and grassy weeds in crops like wine grapes, almonds, vegetables, fruits, and cotton [Wikipedia - Oxyfluorfen].
• Residential weed control: You might find it used in products for controlling weeds around houses, on patios, or driveways [Effective Oxyfluorfen Ec Herbicide For Onion, Tea, Potato].