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How do peptides work in the body?
Almost always the same basic mechanism: a peptide fits a specific receptor or binding site the way a key fits a lock, and that fit triggers a cell to do something — produce more collagen, release a hormone, or dial down a signal.
On this page
In brief
Should you care? Only if you want the mechanism, not just the outcome — this page is the “how” underneath the individual pages, useful background rather than something you need to know to use any specific product.The short version
- The core idea: a peptide’s shape lets it bind a specific target, and that binding is what triggers an effect.
- The consequence: a tiny change in sequence can change what a peptide does entirely, which is why closely related peptides can have very different jobs.
The lock-and-key idea
Most peptides work through a version of the same basic idea: their specific three-dimensional shape allows them to bind to a matching receptor or binding site on a cell, the way a key fits a particular lock. That binding event is what triggers whatever happens next — a cell starting to produce more of a protein, a hormone being released, a nerve signal being dampened. The peptide isn’t "doing the work" directly so much as delivering an instruction that a cell then carries out.
Three examples, worked through
| Peptide | What it binds to / interacts with | What happens next |
|---|---|---|
| Copper peptide (GHK-Cu) | Delivers copper into processes involved in tissue repair signalling | Supports collagen and elastin production |
| Matrixyl 3000 | Recognised by fibroblasts as a signal fragment | Fibroblasts increase collagen and elastin output |
| Argireline | Interferes with the release mechanism at the neuromuscular junction | Modestly reduces the signal telling a muscle to contract |
Why size and shape matter for delivery
Because the mechanism depends on precise shape and binding, how a peptide is delivered matters enormously. A peptide taken orally has to survive digestion, which breaks down most peptide bonds — part of why collagen peptides are pre-broken into absorbable fragments rather than relying on whole collagen. A peptide applied to skin has to cross the skin barrier, which is why many topical peptides are modified with a fatty "tail," as covered on the palmitoyl tripeptide-1 page. The mechanism is elegant; getting the molecule to where it needs to act is usually the harder engineering problem.
References
- General mechanism summary drawn from the individual ingredient pages linked above.