I was on Avonex for 3-4 years. It worked great. Make sure you are hydrated the night of the injection. I usually drank a lot of water and a gatorade. Also think of the area 3 inches down your legs (or wherever the injection site is) as six squares. As you change from the first leg to the second use the same square, when you go back to the first leg go to the second square, so on and so forth (this helps prevent scarring). I wish I knew about this when I started.

I wonder why? Avonex is failing most people with MS and I notice you are in the UK so you might want to read this before you start. I have been on Avonex and it gave me the most awful flu like symptoms and depression every time I took it. I found that if I injected at night before a work day with Ibruprofen then dose up regular throughout the day. The reason I took it on a work night was when I was doing it at a weekend due to the side effects then I would just sloth about being miserable whereas at work I had to put the game face on. I had relapses on Avonex and accrued disabling symptoms. Early and effective is where it’s at these days. https://multiple-sclerosis-research.org/2019/12/diagnose-and-treat-early/