PeptideCompareIndependent research & analysis.
Longer, editorial pieces — no product promotion, no sponsorship.
Inside the box: how Product Verification works
Some supplier profiles carry a Product Verified badge. What it checks, what our unboxing content on social media shows, and where the two meet — and don't.
Research peptides and the EU: what actually changed in 2026
The story going around is that research peptides got their own category in the EU. What the European Medicines Agency actually decided on 9 December 2025, what it means for suppliers and researchers, and why the legal status of research peptides itself hasn't changed.
02Peptides are the last five percent
Training, protein and sleep move outcomes by amounts that dwarf anything a peptide does. Low aerobic fitness carried a mortality risk comparable to smoking in a 122,007-person cohort; resistance training pays off at about an hour a week; muscle gain plateaus near 1.6 g of protein per kg. Where peptides genuinely sit in that stack, and why they belong at the end of the list rather than the start.
American suppliers, now also on PeptideCompare
We now include carefully vetted American suppliers alongside our EU suppliers — some with their own EU warehouse, others shipping directly from the US. What that means for you as a researcher, how we vet them, and why this only strengthens the comparison.
02Why we host reviews ourselves
External review platforms remove research-peptide vendors by category — not for misconduct. Why that's a structural problem, and why we host reviews on our own independent infrastructure so they stay put.
03Your body makes thousands of peptides
Thousands of natural peptides have been identified in the human body, but only about 300 have confirmed bioactivity. The rest are mostly protein breakdown fragments. What that gap means, how the body builds thousands of peptides from a few precursors, and why a big peptidome is not a big menu of usable compounds.
04Why bacteriostatic water gets 28 days
A 28-day limit sits on every multi-dose vial, and every so often someone measures the preservative months later and concludes the rule is overcautious. But the limit is tied to a microbial challenge test, not to a chemical assay — and for a reconstituted peptide the binding constraint is usually the peptide, not the water.
05Fridge vs. freezer
Freezer is not always better. For lyophilized powder, colder wins. For reconstituted peptides, the freezer's freeze-thaw cycle can do more damage than the fridge ever would — here is the actual mechanism, and the aliquoting fix.
How peptides are tested
On the gray market a label is just a claim until a lab confirms it. The levels of testing, where samples fall short, the labs that matter, and how to test individually or as a group.
07Why mislabeled BAC water
Independent reports and community testing have repeatedly flagged marketplace-sourced "bacteriostatic water" that turns out to be plain sterile water or saline — missing the benzyl alcohol preservative entirely. Here's what the difference actually means, and why Pfizer's Hospira-branded product has become the reference point researchers compare everything else against.
08Khavinson bioregulators
A Russian gerontology research program spanning five decades produced more than twenty ultra-short peptides, each proposed to act on a specific organ. Here is the history, the theory, an honest look at the evidence, and an index to every one of the 20 compounds PeptideCompare now tracks.
09NMN tablet vs NAD+ injection
NMN at 500–1000mg in tablet form is more practical, better absorbed, and more cost-effective than direct NAD+ for most protocols. Here is the science behind why.
10All NAD+ precursors explained
Not all NAD+ precursors are equal. Here is a complete guide to every major precursor, how they differ biochemically, and what the evidence says about each.
NAD+ synergists
NMN raises NAD+. But NAD+ is only part of the longevity equation. These compounds amplify the effect — through sirtuins, methylation support, and mitochondrial synergy.
12Senolytics & senomorphics
Senescent cells accumulate with age, releasing inflammatory signals that damage surrounding tissue. Senolytics clear them. Senomorphics neutralize them. Here is everything you need to know.
13What a real COA tells you
A Certificate of Analysis is only as good as the lab that issued it. Here is how to read one, which labs to trust, what to look for, and what contaminants are actually found in substandard peptides.
14What research peptides are actually used for
Peptides are studied for reasons that rarely overlap: ageing biology, purity verification, drug development and shifting regulation. A source-based overview of where peptide research actually stands.
15Why a peptide solution turns cloudy or won’t dissolve
A cloudy vial or undissolved powder usually traces to amino acid solubility, shaking, or the freeze-dried cake itself — documented mechanisms, not “bad water.” What FDA drug labels and the formulation literature actually say.