Here are two molecules you may have read or heard about:
Reseveratrol (which is the upper molecule) is found in red wine, and may be responsible for the so called French paradox. If you haven't come across the French paradox, it is the resilience which French people seem to have to a relatively high fat, unhealthy diet. There is speculation that this is due to the presence of a wonder molecule in red wine, called resveratrol. Of course, nothing has been confirmed, and the explanation may just be that French people eat more healthily and exercise more extensively than researchers appreciate. (And there is always the garlic explanation). Oxybenzone (below) is a molecule found in sunscreen formulations. On an occasional basis claims are made about the potential toxicity of oxybenzone. The FDA is aware of these claims and still ranks oxybenzone as a safe molecule for use in sunscreen.
The chemical formula of both these molecules is: C14H12O3.
However, their three dimensional structures are different (see the image below, again resveratrol is the upper molecule). Different shapes lead to different properties and different properties lead to different effects on living cells.
You can be sure that researchers are examining these molecules carefully. When the origin of the resveratrol effect is confirmed, you can then be sure that researchers will be seeking to create improved versions of this molecule which might perhaps improve life expectancies. In the case of oxybenzone, if its toxicity is confirmed, scientist will be seeking modifications which retain the ability to absorb harmful UV radiation yet remove the toxicity.