There is no constitutional right to sell an Organ.
Even though constitution admit that you had the full right for full freedom to do whatever you want to your body, selling an organ is strictly illegal because it may create a market that could endanger many of human's life if it's left handled by the private sectors who constantly seek ways to cut expenses.
Plessy V. Ferguson was only a landmark decision in the Supreme Court of the United States issued in 1896. The impact of Plessy v. Ferguson allowed the statement "Separate but equal" also known as segregation to become law in U.S. After this event, Jim Crow laws which were a system of laws meant to discriminate against African Americans, spread across the United States.
First, i would develop a similar product to 'create your own yogurt' but doing it by using natural Ingredients that definitely better for the health. After that, i would create a marketing campaign to create an awareness for the existence of my product. For the cherry on top, i would endorse several health and fitness professional to make a comparison review between my products and my competitor's.