# Sex Reassignment Gives Interesting Insights Into Hormones & Pain >[!example] 02 March 2023 #blog A study by Aloisi et al in 2007 gives us interesting insights into how hormones influence pain during the process of sex reassignment.[^1] The study looked at Male to Female (MtF) transsexuals as well as Female to Male (FtM) transsexuals.  They found that a third of the MtF subjects actually developed chronic pain during their treatment with oestrogen. And even those that did not develop chronic pain, they still reported a decreased tolerance to painful events and an enhanced sensitivity to thermal stimuli (both warm and cold). So to simplify… %% [[↑ Oestrogen = ↑ Pain]] %% **↑ Oestrogen = ↑ Pain** Not only that, but when looking at the FtM subjects who had chronic pain before the start of treatment, more than half improved after starting Testosterone treatment.  And they reporting reduced numbers of painful episodes & shorter lengths of those episodes that did occur. So to simplify again… %% [[↑ testosterone = ↓ Pain]] %% **↑ testosterone = ↓ Pain** So does this mean that oestrogen causes pain whereas testosterone improves pain? Unfortunately, it’s not as straight forward as that.  [^1]: Aloisi, A.M. et al. (2007) ’Cross-sex hormone administration changes pain in transsexual women and men.’. Pain, 132 Suppl 1, S60-S67. Available at: https://pubmed.ncbi.nlm.nih.gov/17379410