Copper Peptides vs Exosomes vs Polynucleotides

These three get grouped together as regenerative skincare and priced accordingly. They are not comparable in the way the marketing implies, and the difference comes down mostly to size and delivery route.

We sell one of the three. Read accordingly.

The size problem decides most of this

The rough dermatological heuristic is that molecules above about 500 Daltons struggle to cross the stratum corneum in meaningful amounts. It is a rule of thumb rather than a law, but it is the right first filter.

Roughly Crosses intact skin?
GHK-Cu ~400 Da Plausibly yes
Polynucleotides Tens of thousands of Da and up Very unlikely
Exosomes 30 to 150 nanometres, vastly larger Very unlikely

That single table explains most of the practical difference.

Copper peptides

A small tripeptide bound to copper, at roughly 400 Da. Small enough that topical delivery is mechanistically plausible, which is the low bar it clears that the other two do not.

Evidence: substantial mechanistic literature, thin clinical. We counted it: 186 papers, 3 trials, 0 meta-analyses.

Price: roughly $12 to $150 a bottle across the market.

Polynucleotides

DNA fragments, usually salmon-derived. The evidence base that made them popular comes from injectable use in clinical settings, where the barrier is bypassed entirely.

Topical polynucleotide products borrow that reputation. The molecules are far too large to cross intact skin in meaningful quantity, so a topical version is not delivering what the injectable studies studied. Some formulations use fragmented or low molecular weight versions, which changes the size question somewhat and also changes what you are actually applying.

Not a scam, and the injectable evidence is real. Just do not transfer that evidence to a cream.

Exosomes

Cell-derived vesicles carrying signalling cargo. Genuinely interesting biology and the newest of the three.

Two problems for topical use. Size, by orders of magnitude beyond the threshold. And stability: exosomes are fragile, and keeping them intact through manufacture, shipping and shelf life is a hard problem that a room-temperature serum does not obviously solve.

They are also the most expensive of the three by a wide margin, and the regulatory position on exosome products has been contested. Most of the credible work is in-clinic and post-procedure, applied to skin that has been microneedled or lasered, which is a different route of administration.

How to think about it

If a product is applied to intact skin, molecular size is the first filter and it eliminates a lot. Copper peptides pass it. The other two mostly do not, in their topical forms.

If a product is applied after a procedure, into channels or onto resurfaced skin, the calculus changes completely, and that is where exosomes and polynucleotides have their strongest case. It is also a clinical context rather than a bathroom one, and it comes with its own risks. Why we say wait 24 hours before applying anything to needled skin.

The honest ranking

For at-home topical use on intact skin, ranked by whether the mechanism can plausibly happen:

  1. Copper peptides. Small enough. Thin clinical evidence, but the delivery question is at least answerable.
  2. Polynucleotides. Strong evidence for the injectable, weak transfer to topical.
  3. Exosomes. Most interesting biology, hardest delivery problem, highest price, newest and least settled.

We sell the one at the top of that list, which you should factor in. The size argument is not ours though, and you can check the molecular weights yourself.

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