Is it harmful to take methotrexate?

Yes, if no indicatio: It will be harmful if no indication to take. However, if there is a strong indication- it is something that is tolerable. Just like any other medication, there will be some possible adverse events- and this is something that you have to discuss with your doctor- to weigh the benefit and the risk and make a decision.

Low risk: Methotrexate has relatively low risk, especially if one takes adequate Folic Acid at the same time. The subcutaneous form may have less risk than the oral form but I have both forms well tolerated in literally hundreds of my patients.

Benefits vs. risks.: Methotrexate has been used for the last several decades for rheumatoid arthritis and continues to be the mainstay therapy. It is also used for juvenile arthritis with benefit. Overall, it depends on the indication for the treatment with Methotrexate to ensure the benefits outweigh any potential risks, but certainly has been used successfully in numerous conditions.