Methotrexate is a ubiquitous chemical that is useful as an anticancer agent, to treat psoriasis, rheumatoid arthritis, and also as a chemosterilant pesticide. This drug acts as an antimetabolite by blocking the action of dihydrofolate reductase in cells that are cancerous or skin cells with psoriasis. Unfortunately, other cells are also affected by methotrexate, so serious side effects usually occur with the use of this drug. Some of these side effects are hair and appetite loss, blurred vision, dark urine, and dizziness.