There is a lot of confusion on this issue.

Most of the hormones we use in conventional HRT treatment are identical to what your body will produce . We call them body identical.

However the term bioidentical is used as marketing term by some clinics who  use specially compounded preparations .  Many claim that these products are better or safer than conventional HRT treatment.  Unfortunately these claims are not based on any scientific evidence.

On the contrary these products do not undergo the same checks that conventional products will have to pass in order to be available to patients. That basically means that you have no idea what they contain.

For this reason there are concerns on their safety profile.

They also are far more expensive than conventional HRT as the clinics selling them have a considerable profit margin on the product.

Here is the link to a document produced by the British Menopause society on this issue.

https://thebms.org.uk/publications/consensus-statements/bioidentical-hrt/