As far as I understand, Switzerland does not recognize medical degrees from outside of the EU/EFTA
There is a more convoluted way to get there. They have an "indirect" accreditation route. If your medical degree has been recognized by another EU/EFTA country, and you have been working there for 3 years, then they will recognize the degree. For this you either have to have an EU/EFTA citizenship or have married someone with it.
For example: Being a French citizen, graduating medical school in the US, having that degree recognized in France and working 3 years in France. Or Being married to a German citizen, graduating medical school in the US, have your degree recognized in Germany and then work there for 3 years.
Also, you need to have a C1 level of proficiency in any of the oficial languages. French, German, Italian, romansh(?)
Anerkennt ein Vertragsstaat ein Drittstaatendiplom (erworben ausserhalb der EU/EFTA), spricht man von der indirekten Anerkennung ("Anerkennung der Anerkennung").
www.bag.admin.ch
Residency training is extremely different to what most countries do. I can share more information about the system if needed.
If you wish to do research you don't necessarily need a medical license. So you could approach a research group/PI and apply for an open post doc position, etc. vacancies are usually posted online or you can cold call them. This would obviously mean that your contact with patients will be limited/restricted due to not having a medical license, and you can't undergo further clinical training.