Compared to supplements and food ingredients, drugs often have a stronger and more predictable impact on the body, along with a higher prevalence and severity of adverse effects than natural products found in foods and supplements. Why? There are many reasons, including concentration and coinciding compounds. But let’s assume both are given at a high dose in concentrated form.
Drugs are designed to hit a receptor or other target with reasonably high affinity. Affinity is the ability of a molecule to bind its intended target (a receptor, enzyme or other macromolecule that mediates its therapeutic action).
Drugs are intended to hit that target with forceful purpose. Think of a table with 4 legs that’s a little wobbly and needs repositioning. Kicking one leg with a lot of force might do the trick, but you risk breaking the leg and destablizing the entire structure.
But if you divide the force among the legs, tapping each gently and in a coordinated way, you can still reposition the table while posing a reduced risk of injury to the structure. It might require some patience and strategy, but in the end, the approach was safer.
In general, dietary compounds tend to have low affinity for their targets, and are generally not as selective. They don’t strike receptors, enzymes or macromolecules with a great deal of vigor; rather, they simultaneously tickle many different effectors to enlist a more subtle but coordinated physiological response. The result? Milder effects and better safety.
Integrative Pharmacology 