genetics

Nothing new per se but it's a nice summary. Also ventures into genetic predispositions. https://selfhacked.com/blog/hematocrit/

Genetic architecture of human thinness compared to severe obesity

Several studies have been published on the subject of genetic predisposition to certain side effects of testosterone. Here is the latest The role of the androgen receptor CAG repeat polymorphism and other factors which affect the clinical response to testosterone replacement in metabolic...