How does the body know the difference between natural and synthetic chemicals or compounds? If the synthetic chemical is identical to the natural compound the body has no clue. The body’s reaction to a substance is like a lock and key. When a hotel is built the “natural” keys come with the lock but as keys get lost new “synthetic” keys are made. The door still opens and let’s whomever has a key that fits the lock into the room.
Either way the person can enter the room and do whatever he or she wants. In our bodies receptors are one type of lock and any compound (the key) that can bind to the receptor can enter the cell and cause some reaction. So the body will react to a synthetic compound in exactly the same way as it does to a natural product as long as the compound “fits” the receptor.
Prescription drugs are not usually identical to the natural compound but they are close enough so the body recognizes them. In order for a synthetic compound to work in the body there must have already been a receptor being used by a similar natural compound.
Drugs are designed based on receptors and compounds are tested in animal cells to see which ones will cause a reaction by binding to the receptors. Scientists will modify compounds until they get the reaction they want. Removal or addition of a piece of a compound can cause it to have a weaker or stronger effect than the bodies’ own compound.
Herbs have natural compounds that can be recognized by various receptors in the body. This is why herbs can and do work.