Hello, Welcome to healthcare magic. I understand that you are having psoriasis and are concerned about the treatment. Methotrexate is a very effective drug for controlling psoriasis. The usual adult dose is 10-15 mg per week which is calculated based on the body weight. We usually start at 2.5 mg per week and if there are no side effects gradually escalate the dose. It usually takes 6 weeks ( 6 doses) for you to notice a significant reduction in scaling and redness. Methotrexate is a toxic drug if taken without supervision. Please meet your dermatologist regularly and get a blood work up done to look for blood cell counts and liver function tests. If taken under supervision, it is a very good medicine and most of the patients are happy with it. Hope this helps you. Take care.