For example, vitamin A is a beneficial antioxidant with a number of healthful uses, but natural vitamin A can be unstable and breaks down easily. And if a plant has been grown in less than ideal conditions or has been exposed to contaminants, its vitamin A may not be as effective as it should be. This is where synthetics can be of use. Knowing what types of molecules combine to make up vitamin A, scientists can take some of the molecules from one source and the rest from a second source. When the molecules from these two sources are combined, vitamin A is created.
Synthetics can also be useful if a plant has both beneficial and undesirable qualities.
Some plants contain chemical compounds that offer soothing or moisturizing benefits, while also containing other compounds that cause allergies or irritation. A good example of this is cinnamon. Cinnamon contains a compound that is useful in preventing sunburn. But cinnamon also contains an oil that can be irritating to the skin and eyes. Simple chains of molecules are easy to recreate through synthesis.