Why don't they use natural ligands/signaling molecules as drugs instead of using chemical molecules as drugs?

We do use many signaling molecules as peptide drugs these days like growth factors, hormones etc .similarly there are thousands of signaling molecules reported to have involved in particular cell physiology.Their functions like tissue regeneration, killing cancer cells, immunity etc are very well documented and confirmed by thousands of research studies.so why don't we just use them directly as drugs instead of trying to find chemical molecules with unknown role in human system to act as a exogenous ligand to activate the same receptors? and of course with tones of issues like off target and side effects etc.Now so many signaling molecules have been discovered that are involved in killing cancer cells in our body. so why can't we just use those known natural signaling molecules as a drug to kill cancer cells just like we use other peptide drugs like insulin etc? One obvious reason will be cost, and ease of production with chemical drugs but is there any other valid reason to use chemical drugs instead of known natural signaling molecules? Thank you.


By chemical molecules i mean synthetic drugs

Update 2:

another possible answer i found is that peptide drugs can only be injected but synthetic drugs can be taken orally.

3 Answers

  • Bob B
    Lv 7
    5 years ago
    Favorite Answer

    We do use these for various things- insulin is one of the best examples.

    The problem with your approach is that in many cases, there is no natural ligand or signalling molecule that actually does the job we want our drug to do, or they interact with other systems in the body as well (many signalling molecules have many roles in the body), so it makes it very hard to rely solely on them. Synthetic drugs can be made to target many different receptors or other targets that we don't have a convenient natural signal molecule for.

    Bacterial and viral infections are good examples- although we do make antibodies, we don't make inhibitors of many bacterial proteins or processes, and the right molecule can prove very effective against such things, which is why antibiotics work so well.

    Route of administration is one issue as you suggested- most natural molecules need to be injected. Production is also an issue; small molecules are usually easier to make in bulk than natural proteins or peptides.

  • 5 years ago

    Sodium Fluoride is actually a byproduct of the nuclear energy program. Fluorine gas is used in uranium enrichment. It is a strong acid neutralized with sodium making it a salt. In the 50s there was a huge excess after processing uranium. It was simply dumped into rivers. Many claimed it was a communist plot when in actuality it was just typical corporate America at work. Taking a waste product turning it into health product, and selling it to municipalities as a way to decontaminate their water. Someone later found out it helped prevent tooth decay.

  • Joe
    Lv 6
    5 years ago

    Everything is made of chemicals so your dichotomy is false.

    You do not suggest how these naturally occurring signalling molecules can be farmed and harvested or whether they are universally compatible with different genomes. Could any of that be the obstacle?

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