I am also wondering about collagen ..... I've had lumpectomy 12/23 and currently on Tamoxifen . I am 55- noticed thinning hair... Really thought about some internal help for that reason but afraid of it after some research. My oncologist didn't have an opinion about collagen ... she just said there is no interaction with Tamoxifen ... Not sure what to do ...
Ugh ! Tired of analyzing and thinking what can help and what might be hurting. Wishing you all the best ! Love and peace !