Is there any medication for DID?
Unfortunately, little to no research has been done on the interactions of various medications with DID patients or their symptoms and functionality. For that reason, many professionals out in the field report their anecdotal findings and try to come up with a general guideline for medications and their interactions with particular to DID systems.
DID is almost always co-morbid (which means more than one mental health disorder is present) with PTSD or more specifically C-PTSD due to ongoing childhood trauma. There are medications for PTSD-related issues, with less study on their effects and efficacy in the case of chronic childhood trauma or DID overall — and less study on biological females with PTSD.
DID is always dissociative in nature, and there is not much study of medications with dissociative symptoms either. Some medications may increase symptoms of dissociation (such as Dextromethorphan, an ingredient in some cough syrups, for which dissociation is a known side effect) and some folk with DID find that problematic.
Since this entire topic is out of scope of a peer-run website, please see the article here, or refer to professional associations for Trauma treatment and research to see whether they have any new news or latest discoveries in the field of DID and medication.
In the time being, "there is no medication for DID" holds true. This is not a chemical disorder. Medications may help certain co-occurring symptoms (like anxiety, or depression), but there is nothing known which will remove or eradicate the voices in a DID person's head in a "good" way.
There has been research in tracking down the brain pathways that regulate dissociation and neurological chemistry involved, so something that prevents or changes the experience of dissociation may happen in the future, but it's unlikely to treat DID and make the headmates go away — it may regulate or interrupt other dissociative symptoms such as amnesias, depersonalization or derealization, etc.