I am sorry about the problems you are experiencing. Having lived with a MS diagnosis for 10 years I suppose you understand that it s a chronic condition. While there are unfortunately no treatments to extinguish the disease these days there are many available treatments to slow down its progression and disability. Some of them have been available for more than a decade like Interferons, but there are many new therapies which have come out in the last few years, Tecfidera being one of them. Since it s a disease with a course of many years, to reach a conclusion about the efficacy of this or other new drugs a follow up of many years is needed. The same applies to its long term side effects. The most common side effects known till now are flushing and gastrointestinal problems, mostly in the first month. So it shouldn t be the cause of your chest pain. As I said with time new side effects may be reported, but in this drug s particular case we are more confident because it has been used for a long time already for the treatment of a skin condition called psoriasis so its side effects are better known compared to other new treatments. I think you should report it to your doctor though. It may be a simple case of anxiety which if frequent and bothersome can be treated, but also other heart or respiratory system problems must be excluded. I hope to have been helpful to you. Feel free to ask further questions.