Hi SharonDavies, I started on Letrozole 3 weeks ago. No significant side effects at first, just some mild hot flashes. But now am noticing some joint pain in my shoulders, the right shoulder has a rotator cuff injury and it hurts like crazy at night. The left arm has lymphedema from a major surgery due to broken arm. The lumpectomy and sentinel node biopsy on my left side kinda worsened my lymphedema. But working with physiotherapist has helped me. But the Letrozole is giving me some joint pains and My left arm also hurts at night. Hopefully the side effects will subside as my body adjusts to Letrozole. Hope you are doing well and have no major issues with Letrozole.