The plain-English peptide encyclopedia
Every peptide, explained straight.
Hair, muscle, weight loss, sleep, sex, longevity: what actually works, what’s hype, and what’s just not worth the needle. No products, no sales pitch, no BS.
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Latest research explained
Cagrilintide vs CagriSema: What Is the Difference?
Cagrilintide is a single experimental molecule. CagriSema is the combination of cagrilintide and semaglutide that Novo Nordisk tested in large trials and sent to the FDA. Here is how they differ, what the trials compared, and where approval stands.
Published September 15, 2026
Ecnoglutide Approval Status: China, the US and Europe
Approved in China for type 2 diabetes and weight management in early 2026. No FDA approval or EU authorization found as of September 15, 2026. A dated, sourced status table and a timeline that separates trials, applications and approvals.
Updated September 15, 2026
Efinopegdutide Clinical Trials: Is It in Phase 3? Every Trial, the Results, and Approval Status
Efinopegdutide is often searched with 'phase 3', but no Phase 3 trial exists as of September 2026. Here is every registered trial, what the finished ones found, and what is still unknown.
Updated September 15, 2026
GHRP-6 Approval and Sports Rules: What "Research Only" Means
"Not approved," "illegal" and "banned in sport" are three different findings. We checked FDA records and WADA's 2026 list to separate them for GHRP-6.
Published September 15, 2026
Matrixyl INCI Names: Original, 3000 and Synthe'6 Explained
Which peptide is inside Matrixyl, Matrixyl 3000 and Synthe'6, what else is in the supplier's blend, how to spot them on a label, and what each has actually been tested for.
Updated September 15, 2026Monthly Weight-Loss Injections? What MariTide Trials Are Testing
MariTide is tested as a monthly injection, and newer trials try gaps of 8 or 12 weeks. Here is what each study actually asks, what has reported, and what is still a plan.
Published September 15, 2026What everyone’s reading
Is BPC-157 legal, or are you rolling the dice?
02Weight LossOzempic vs Zepbound: which one actually wins?
03HairThe best peptide for hair growth (and the hype to skip)
04MusclePeptides for muscle: what works vs what's banned
05LibidoPeptides for a better sex life, explained without the cringe
06Buyer BewareHow to spot a fake peptide before you get burned
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Peptides people look up
Efinopegdutide
ResearchMASH and MASLD (forms of fatty liver disease), and earlier, obesity
MariTide
ResearchObesity / weight loss and type 2 diabetes
Ecnoglutide
ResearchType 2 diabetes and weight management (approved in China); sleep apnea and knee osteoarthritis with obesity, and teen obesity (in trials)
Cagrilintide
ResearchWeight loss and appetite control (often tested with semaglutide as 'CagriSema')
Semaglutide
ApprovedType 2 diabetes and chronic (long-term) weight management
Tirzepatide
ApprovedType 2 diabetes and weight management
BPC-157
ResearchTissue, tendon, and gut healing
SS-31
ApprovedBarth syndrome (approved use), primary mitochondrial myopathy, heart and eye conditions
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Peptides are confusing and full of hype. We explain them in plain words, keep skincare peptides separate from the injectable kind, and help you tell what’s real from what’s marketing.
What Peptide Skin Science is here to do
Peptides 101
Quick answers
What are peptides?
Peptides are short chains of amino acids: the same building blocks that make up proteins. In your body they act as messengers that tell cells to do things like make collagen, release hormones, or repair tissue. In products, "peptide" covers three very different things: cosmetic peptides in skincare, research peptides sold as unapproved chemicals, and approved peptide medicines.
Are peptides safe?
It depends entirely on which peptide. Cosmetic peptides in regulated skincare are generally considered safe to put on your skin, and approved peptide medicines have known safety profiles when prescribed. But "research" peptides sold online for injection are not approved, not quality-checked, and their safety in humans often isn't established, which is why we flag those clearly.
Are peptides legal?
Cosmetic peptides in skincare are legal to sell and use, and approved peptide medicines are legal with a prescription. Many popular "research" peptides such as BPC-157 or TB-500 are not approved as medicines and are sold as "research chemicals". Being legal to sell as a chemical is not the same as being safe or legal to use on yourself, and many are banned in sport.
Do peptides actually work?
Some do, some don't, and plenty are over-hyped. A few peptides have strong human evidence: for example the GLP-1 weight-loss medicines. Many "research" peptides only have animal studies behind them. We tell you honestly which is which on every page, and cite the real research.
What's the difference between skincare peptides and injectable peptides?
A lot. Cosmetic peptides go on your skin and are limited to claims about how skin looks. Injectable "research" peptides are a completely different, largely unregulated category. We keep the two strictly separate so marketing never blurs the line.
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