Can weight increase by taking Cital and Doxepin?

According to the Summary of Product Characteristics, Doxepin and Cital may cause weight gain, but these are rarely reported side effects (in the case of Cital - from 1 in 1000 people to 1 in 100 people and Doxepin - less than 1 in 10 000 people). Probably a slight increase in body weight in your case is caused by the phase of the menstrual cycle. Before the period, hormonal changes occur, as a result of which water is retained in the body, therefore the weight can vary from about 1.5 to 3 kg. Do not worry, and if you are concerned about this condition, I recommend increasing the supply of water and limiting the consumption of salt. I enclose additional materials that may be of interest: https://www.gdziepolek.pl/artykuly/fakty-i-mity-o-zatrzymaniu-wody-w-organizmie