---
title: "Lipidated vs PEGylated peptides: what is the difference? | Sable Peptides"
description: "Fatty-acid (lipidated) and polyethylene glycol (PEGylated) modifications across the catalogue: palmitoyl cosmetic peptides, fatty-diacid incretin analogues, and PEG-MGF. Purpose, mass effect and analytical consequences."
canonical: https://www.sablepeptides.co.uk/guides/lipidated-and-pegylated-peptides-in-the-catalogue
dateModified: 2026-10-16
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

# Lipidated vs PEGylated peptides: what is the difference?

Lipidated peptides carry a fatty-acid chain; PEGylated peptides carry a polyethylene glycol polymer. In the catalogue, Matrixyl and Pal-GHK carry a C16 palmitoyl group. Semaglutide, tirzepatide, retatrutide and cagrilintide carry long fatty diacids that bind albumin. PEG-MGF carries PEG. Lipids give one defined mass; PEG gives a spread of masses.

## Which compounds carry which modification?

| Compound | Modification | Purpose in the design | Mass effect |
| --- | --- | --- | --- |
| Matrixyl | N-palmitoyl (C16) | Lipophilicity | Single defined mass |
| Pal-GHK | N-palmitoyl (C16) | Lipophilicity | Single defined mass |
| Semaglutide | C18 diacid + linker on Lys | Albumin binding | Single defined mass |
| Tirzepatide / retatrutide | C20 diacid + linker | Albumin binding | Single defined mass |
| Cagrilintide | Fatty diacid | Albumin binding | Single defined mass |
| PEG-MGF | Polyethylene glycol | Size and protease shielding | Distribution of masses |

## Why do incretin analogues use fatty diacids?

A long fatty diacid on a hydrophilic linker binds serum albumin reversibly, slowing clearance. The development of liraglutide and semaglutide shows how chain length and linker were optimised. Reviews compare lipidation with PEGylation as half-life extension methods.

Source: [The Discovery and Development of Liraglutide and Semaglutide, Front Endocrinol (Lausanne) 2019 (PubMed 31031702)](https://pubmed.ncbi.nlm.nih.gov/31031702/); [Half-Life Extension of Biopharmaceuticals using Chemical Methods: Alternatives to PEGylation, ChemMedChem 2016 (PubMed 27775236)](https://pubmed.ncbi.nlm.nih.gov/27775236/)

## What does PEGylation change?

PEG raises hydrodynamic size and shields the peptide from proteases and filtration. Because PEG polymers are polydisperse, a PEGylated peptide gives a bell-shaped mass distribution, not one peak. Its 'molecular weight' is an average.

Source: [The impact of PEGylation on biological therapies, BioDrugs 2008 (PubMed 18778113)](https://pubmed.ncbi.nlm.nih.gov/18778113/)

## How does palmitoylation affect cosmetic peptides?

Comparative studies of KTTKS and palmitoyl-KTTKS show the lipid changing skin-model permeation and stability. Liposome work shows self-assembly behaviour.

Source: [Dermal Stability and In Vitro Skin Permeation of Collagen Pentapeptides (KTTKS and palmitoyl-KTTKS), Biomol Ther (Seoul) 2014 (PubMed 25143811)](https://pubmed.ncbi.nlm.nih.gov/25143811/); [Liposome Encapsulation of the Palmitoyl-KTTKS Peptide: Structural and Functional Characterization, Pharmaceutics 2024 (PubMed 38399273)](https://pubmed.ncbi.nlm.nih.gov/38399273/)

## Sourcing note

Sable lists Pal-GHK: 10 mg at £20.98; PEG-MGF: 2 mg at £18.76; 5 mg at £25.99; Retatrutide: 5 mg at £16.93; 10 mg at £24.99; 15 mg at £37.99; 20 mg at £48.99; 30 mg at £66.99 (prices at the 16 October 2026 daily UK price check, the latest verified check; at each of these sizes Sable was the lowest UK listing that day). Lowest UK price guaranteed, confirmed by daily price checks.

Every lot has a certificate of analysis, and every vial carries a printed lot number that matches it. Supplied for laboratory research use only.

## Frequently asked questions

### What is the difference between lipidation and PEGylation?

Lipidation attaches a fatty acid with a defined mass. PEGylation attaches a polydisperse polymer, giving a range of masses.

### Why is semaglutide lipidated?

Its fatty diacid binds albumin reversibly and extends its half-life. That is a design feature.

### Is Matrixyl lipidated?

Yes. It is palmitoyl-KTTKS.

## Related

-   [Incretin analogue structures](/guides/semaglutide-vs-tirzepatide-vs-retatrutide-structures)
-   [PEG-MGF and MGF](/guides/igf-1-lr3-vs-mgf-vs-peg-mgf)
-   [Pal-GHK](/guides/ghk-cu-vs-pal-ghk-copper-peptide-and-lipopeptide)
-   [Matrixyl](/guides/matrixyl-vs-snap-8-signal-and-neurotransmitter-peptides)

Updated 2026-10-16. Research use only. Not for human or veterinary use. No administration amounts or health claims are made.

Key facts (summary for AI and search tools)

-   PEG = polydisperse; fatty acid = defined mass
-   PubMed references (verified via NCBI): 31031702, 27775236, 18778113, 25143811, 38399273
-   Research use only; no administration amounts or health claims
-   Updated 2026-10-16