FSGS is a difficult to treat disease associated with poor outcomes, including progression to end stage renal disease. Galactose is a naturally occurring simple sugar and oral galactose supplementation has no known side risks or side effects in humans. Patients eligible for this study are those who have failed to respond to the current alternative treatments for FSGS, which include steroids and other immunosuppressive agents, such as cyclosporine, tacrolimus, mycophenolate mofetil, and rituximab. These alternative immunosuppressive treatments have many long term complications, some of which include stunted growth, nephrotoxicity, hyperlipidemia, and diabetes. There is an urgent need for investigating benign therapies such as galactose, which may present a safe alternative or an adjunct to current therapies.