Oral retinoids work in a similar way as topical retinoids. This form of retinoid is taken in pill form, and treatment typically lasts for several months. While they can be effective in treating psoriasis, oral retinoids also have potential side effects, including dry skin, chapped lips, nosebleeds, and liver damage. These medications require careful monitoring by a healthcare provider. In addition, oral retinoids are not recommended for women who are pregnant or planning to become pregnant, as they can cause birth defects. Therefore, it is important to discuss the risks and benefits of using oral retinoids with a healthcare provider before starting treatment. Oral retinoids are only suggested for those with severe psoriasis. Severe psoriasis is generally defined as having psoriatic plaques on more than 30% of the body or on large portions of the face, palms, or soles.