If you're a non-physician who owns or wants to own a med spa in a Corporate Practice of Medicine state, the management services organization is almost certainly the structure your attorney reached for — and for good reason. It's the legitimate, widely used answer to a hard legal problem. It's also the structure most likely to be built as a costume, and a costume is exactly what a regulator or an acquiring company's counsel is trained to see through. Understanding how the MSO actually works, and where it breaks, is the difference between a durable business and a defective one wearing nice paperwork.
This is general education for owners, not legal advice. CPOM and MSO rules vary by state; build and review your structure with healthcare counsel licensed where you operate.