Research Peptide Fundamentals: Claims Are Cheap, Evidence Is Expensive

The short version

Peptide Bargains is a reading desk, not a shop. Nothing here is for sale, no product is compared to another on price, and no dose is recommended to anyone. The name is a joke about the field, and it is meant to be read backwards.

In peptide research the cheapest thing available is a confident claim. Anyone can make one, it costs nothing to produce, and there is an enormous supply. The expensive thing is evidence: a trial with enough people in it, run long enough, against a group that did not get the compound, measuring something that actually matters to a person rather than something convenient to measure.

So this desk prices findings instead of products. For each of three well-studied compounds — semaglutide, NAD+ and GHK-Cu — it asks what the underlying research cost to produce, and then how much belief that purchase honestly buys. A surrogate marker (a laboratory number standing in for health, such as a blood level) is cheap to move. A hard outcome (a heart attack, a hospital admission, kidney failure) is expensive to move, and worth far more when it moves.

What counts as a bargain on this desk

A bargain here is not a discount. It is a finding whose supporting evidence cost far more to generate than the claim attached to it — where the claim is modest and the machinery underneath is enormous. The opposite case, and by volume the more common one, is a claim that badly outruns what anyone paid for it.

Four things set the price of a finding, and they are the only four this desk grades on:

• How many people. A result in forty-five people and a result in seventeen thousand are not the same kind of object, however similar the headline sounds.
• How long. Six weeks of a marker and seventy-two weeks of a body are different purchases.
• Against what. A randomised placebo group is the single most expensive component of a trial and the one that does the most work. Without it, a study reports what happened, not what the compound did.
• Measuring what. A blood level, a gene-expression table and a stroke are three different currencies, and they do not convert at par.

Those four levers explain nearly the whole difference between the three compounds gathered here. None of this grades the compounds themselves as good or bad. It grades what is knowable about them at today's price.

What a research peptide actually is

Peptides are short chains of amino acids — the same building blocks that make proteins, only much smaller. The body makes thousands of them and uses them as signals: instructions passed between cells telling tissue to grow, to release insulin, to repair itself, to stop being hungry.

The three compounds on this desk sit in three completely different regulatory places, and that placement is itself a piece of evidence. Semaglutide (Ozempic, Wegovy, Rybelsus) is an approved prescription medicine for defined indications in adults, which means a regulator has already examined a dossier of trials and agreed the benefit was demonstrated. NAD+ is not an approved drug at all; it and its precursors are sold as dietary supplements, and the injectable forms are compounded rather than approved. GHK-Cu has no approved therapeutic indication by any route; topical Copper Tripeptide-1 is a legal cosmetic ingredient with a long safety record, while injectable use is unapproved and research-only.

Approval is not a verdict on whether a compound does anything. It is a reliable signal of how much evidence was bought — because the price of admission is a controlled trial programme, and nobody pays that price accidentally.

Three compounds, three price brackets

Semaglutide sits at the top of the market. Its record includes a cardiovascular outcome trial in 17,604 adults with established cardiovascular disease and overweight or obesity but no diabetes, which reported a 20% relative reduction in major adverse cardiovascular events versus placebo ^[3], and a kidney-outcome trial in 3,533 people with type 2 diabetes and chronic kidney disease reporting a 24% lower risk of major kidney events ^[2]. Those are events in people's lives, counted over years, against a placebo group. That is as expensive as clinical evidence gets, and it is why the claims made for semaglutide are unusually well-covered by what was paid for them.

NAD+ sits in the middle, with an unusual shape. The surrogate is bought outright: nicotinamide riboside raised whole-blood NAD+ by 22%, 51% and 142% across ascending doses over eight weeks in healthy overweight adults ^[10], and oral NMN raised blood NAD+ dose-dependently over sixty days in a multicentre double-blind trial ^[7]. The clinical destination, however, is not bought. A 2025 review of the human evidence concluded that trials have shown limited efficacy and that data on tissue-specific NAD+ dynamics remain sparse ^[6].

GHK-Cu sits at the bottom on price and near the top on claim volume. The most-quoted figure — that GHK modulates thousands of human genes — traces to an analysis reporting a shift in 31.2% of genes at a 50%-or-greater change threshold, and the source itself notes the popular round number is an extrapolation from a table on the order of 2,100 genes ^[14]. The strongest controlled human result is a six-month trial in 45 men, and the product tested was a combination of 5-aminolevulinic acid with the GHK peptide rather than GHK-Cu alone ^[15].