The first hrt prescribed to me to treat hair loss, was norethisterone based. Unfortunately, it scarred my scalp. Norethisterone is an androgen based compound so if your scalp is sensitive to testosterone. It will not increase or cause your hair loss. So is helpful to know the compounds in hrt's available. I have uploaded a chart of hrt and their compounds. I apologise for the size of the screen shot. Hopefully the screenshot size can be increase when uploaded. The screenshot is slightly out of focus so may be better to copy the below title into Google. There wasn't a link to copy and it was difficult to upload and save the chart. But the information is easily found on Google.
apc-clindoc-010-hrt-formulary-and-treatment-guidance