I was in the same position as you, unable to take finasteride due to side effects. Regardless I got a hair transplant in 2017 at age 25. I don't regret getting it, I wish I went with a better surgeon however. Your hair loss doesn't appear to be too aggressive so restoring a NW1 hairline wouldn't be too difficult & it should be maintainable until you're nearly 30 or possibly into your 30s. I just got my second transplant at 31, this was more to add density from my first transplant/ I've probably lost between a quarter and half a norwood between transplants. I would highly recommend adding weekly microneedling along with topical minoxidil as well
Your 20s are the prime years of your life, you don't want to be hindered by hair loss. I say go for it, with a reputable surgeon of coarse