What Is Lipidation? How a Fatty Acid Makes a Peptide Last Longer

Published October 2026 · Patriot Labs Research Team · ~20 min read

The short answer

Lipidation is the attachment of a lipid — almost always a fatty acid — to a peptide. In peptide drug design, that fatty acid binds reversibly to albumin, the most abundant protein in blood, so the peptide travels bound to a large, long-lived carrier instead of circulating free. Because albumin is too big to be filtered by the kidney and is recycled rather than destroyed, the lipidated peptide is cleared far more slowly and shielded from enzymes, turning a half-life of minutes into one of days. The fatty acid itself has no target of its own; it is a molecular grappling hook for albumin.

That one idea is behind the long-acting peptides of the current era. Native glucagon-like peptide-1 survives roughly two minutes in the blood; semaglutide, the same peptide fitted with a fatty-acid chain, lasts about a week.^[1][2][6] The rest of this guide takes the concept apart: what lipidation is in cell biology before it was ever a drug trick, why a fatty acid slows clearance so much, the attachment chemistry — the acylation bond, the gamma-glutamyl and OEG linkers, the choice between a monoacid and a diacid and how long the chain should be — the GLP-1 and insulin case studies, the cost in potency, the link to oral delivery, and how a lipidated peptide is told apart from its parent in the laboratory.

What lipidation actually is

Lipidation means joining a lipid to a peptide or protein. A lipid is simply a water-avoiding (hydrophobic) molecule; the lipid used on peptide drugs is nearly always a fatty acid, a long hydrocarbon chain ending in one or two carboxylic-acid groups. Attaching that greasy chain to an otherwise water-loving peptide gives the molecule a split personality: a polar, functional peptide head and a hydrophobic tail that wants to escape water by burying itself in a membrane or in the fatty pocket of a carrier protein.

It helps to separate two worlds that use the same word. In cell biology, lipidation is a natural post-translational modification: enzymes attach specific lipids to specific proteins to control where those proteins sit in the cell, and the purpose is almost always membrane anchoring and localisation.^[3] In drug design, lipidation is a deliberate chemical modification: a fatty acid is attached to a therapeutic or research peptide not to anchor it to a membrane but to make it bind the blood protein albumin, so that it lasts longer.^[1] The chemistry is related, but the goal is different. Most of this guide is about the drug-design use, because that is what the term usually means when it is applied to research peptides; but the natural forms are worth knowing, because they are where the idea came from and because they explain why the word covers more than one kind of attachment.

The specific, most common form of lipidation on peptide drugs is acylation: forming an amide bond between the carboxyl group of a fatty acid and an amino group on the peptide, usually the side-chain amine of a lysine. “Fatty-acid acylation” and “lipidation” are therefore used almost interchangeably for these molecules, although lipidation is the broader term that also takes in the non-fatty-acid lipids described next.

Lipidation in nature: the four kinds

Before lipidation was a drug strategy it was a widespread natural modification, and cells use several chemically distinct versions. Each attaches a different lipid, to a different amino acid, through a different bond, and almost all of them exist to tether a protein to a membrane or to govern where in the cell it works rather than to change how long it lasts in blood.^[3] Knowing them makes clear that the drug use — a fatty acid added to recruit albumin — is one narrow application of a much broader chemistry.

N-myristoylation

A 14-carbon saturated fatty acid, myristic acid, is attached through an amide bond to a glycine at the very start (N-terminus) of a protein, by the enzyme N-myristoyltransferase, usually as the protein is being made. On an N-terminal glycine the bond is effectively permanent. Its role is membrane anchoring and correct protein localisation.^[3]

S-palmitoylation

A 16-carbon palmitate is attached to the sulphur atom of a cysteine side chain through a thioester bond, by a family of DHHC enzymes (humans have roughly two dozen). Crucially this bond is reversible — dedicated thioesterase enzymes can remove the palmitate — so palmitoylation acts like a switch, letting a cell add and strip the lipid to move a protein on and off membranes and tune its signalling, trafficking and stability.^[3]

Prenylation

An isoprenoid lipid — either a 15-carbon farnesyl or a 20-carbon geranylgeranyl group — is attached through a stable thioether bond to a cysteine near the C-terminus, within a recognition motif often written as the “CAAX box.” Prenylation is the modification that anchors the small GTPase signalling proteins of the Ras, Rho and Rab families to membranes, which is why the enzymes that carry it out have been studied so heavily in cancer research.^[3]

Cholesterylation and GPI anchors

Two further forms attach larger or more complex lipids. In cholesterylation, a cholesterol molecule is joined covalently to a protein — the classic case is the Hedgehog signalling protein, which attaches cholesterol to its own C-terminus by self-processing during development. A glycosylphosphatidylinositol (GPI) anchor is an elaborate glycolipid built in the secretory pathway and joined to a protein’s C-terminus; more than 250 human proteins are held to the outer face of the cell membrane this way.^[3] Both, again, are about location, not longevity.

Why a fatty acid extends circulating half-life

A lipidated peptide lasts longer in the blood mainly because its fatty acid makes it ride on albumin. Everything else follows from that one binding event.

Human serum albumin is the most abundant protein in plasma, present at roughly 0.6 millimolar, and it is the body’s natural fatty-acid transporter: its structure contains several hydrophobic pockets that evolved to carry free fatty acids around the bloodstream. A crystallographic study of albumin loaded with fatty acids mapped these as an asymmetric set of binding sites distributed across the protein.^[4] A fatty acid bolted onto a peptide slots into one of those same pockets, so the peptide spends most of its time bound to albumin, in equilibrium with a small free fraction.^[1][3] For liraglutide, for example, only on the order of one to two percent of the drug is in the unbound form at any moment.^[7]

Being bound to albumin changes the peptide’s fate in four reinforcing ways:

• It escapes kidney filtration. The kidney’s filtration barrier removes small molecules from the blood, but albumin, at about 66 kilodaltons, is too large to pass. A peptide that is usually bound to albumin is effectively hidden from the filter it would otherwise slip straight through.^[1]
• It inherits albumin’s long life. Albumin itself survives for weeks rather than hours, because it is rescued from degradation by the neonatal Fc receptor (FcRn) and recycled back into circulation. A peptide travelling with albumin benefits from that same recycling while it is bound.^[1]
• It is shielded from enzymes. While the peptide sits against albumin, proteases in the blood — including DPP-4, which chews up native incretin peptides in minutes — reach it less easily. Acylated GLP-1 analogues degrade far more slowly than the wild-type peptide in the presence of DPP-4.^[6]
• Only the free fraction acts. Because the peptide is released from albumin gradually, the carrier behaves as a slow-release depot: a reservoir that trickles out active peptide over time rather than delivering it all at once.^[1][3]

Some lipidated molecules add a second, related mechanism on top of albumin binding: the fatty acid also drives the peptide to self-associate, forming small clusters or, in the insulin case, larger ordered assemblies that dissolve slowly after injection. That adds a depot at the injection site to the depot in the blood, as described below for insulin degludec.^[1]

How the fatty acid is attached: the chemistry

Turning a peptide into a long-acting lipidated one is not just a matter of gluing a fatty acid anywhere. Four design decisions — where to attach, what linker to use, which fatty acid, and how long — largely determine whether the result binds albumin well while keeping its activity.

The attachment: acylation at a lysine

The fatty acid is almost always joined by acylation — an amide bond between the fatty acid’s carboxyl group and an amino group on the peptide. The preferred anchor is the ε-amine on a lysine side chain, because it sticks out from the peptide surface and can be targeted selectively. To make the attachment clean and single-site, designers often first remove any other reactive lysines: in liraglutide and semaglutide the only other lysine, at position 34, is swapped for arginine so the fatty acid can only attach at lysine 26.^[3][6] In manufacturing, the target lysine is protected while the peptide chain is built and then selectively deprotected so the lipid fragment is added last.^[9]

The linker: gamma-glutamyl and OEG spacers

A fatty acid attached flush against the peptide would bury part of the peptide’s surface and bind albumin poorly. The solution is a linker that holds the fatty acid out at a distance. The workhorse is a gamma-glutamyl (γ-Glu) spacer: a glutamic-acid unit joined through its side-chain (gamma) carboxyl rather than its backbone, which adds length and a negative charge. Newer designs extend the reach further with one or two OEG units (short oligo-ethylene-glycol spacers, chemically 8-amino-3,6-dioxaoctanoic acid, also written AEEA or “mini-PEG”). Semaglutide’s linker is a γ-Glu followed by two OEG spacers; tirzepatide uses a γ-Glu with two AEEA units.^[2][3][5] These hydrophilic spacers improve solubility and albumin affinity and keep the fatty acid from smothering the peptide’s active region.^[15]

The fatty acid: monoacid versus diacid

The fatty acid itself comes in two flavours. A monoacid has a single carboxyl group — the one used to attach it — so its far end is an ordinary methyl tail; liraglutide’s C16 palmitic acid is a monoacid. A diacid carries a carboxyl at both ends, so the end pointing away from the peptide is a charged carboxylate; semaglutide’s C18 and tirzepatide’s C20 diacids are of this type. The terminal carboxyl of a diacid appears to anchor more securely in albumin’s fatty-acid pockets and resists being metabolised, and diacids generally give stronger albumin binding and longer action than a monoacid of similar length.^[1] This is a major reason the once-weekly molecules use diacids while the once-daily liraglutide uses a monoacid.

Chain length

Length is the final lever. Within the usable range — roughly C14 to C20 — a longer, more hydrophobic chain binds albumin more tightly and lengthens half-life. A systematic study of GLP-1 derivatives established exactly this dependence on fatty-acid length, polarity and bulkiness, and found that the gain is not unlimited: beyond a point, a longer or bulkier chain costs receptor potency and solubility without buying proportionally more duration.^[6] The chain is therefore tuned per peptide rather than simply maximised.

The GLP-1 and insulin story

Lipidation’s clearest demonstration is the incretin and insulin field, where the same chemistry was dialled up step by step to go from minutes to a week.

From a two-minute peptide to a weekly one

Native glucagon-like peptide-1 is almost useless as a drug on its own: it has a plasma half-life of about two minutes, because the enzyme DPP-4 cleaves it at the bond between positions 8 and 9 within moments of release, and the kidney clears the rest.^[8][7] The engineering challenge was to keep that peptide’s activity while stopping it from vanishing.

Liraglutide was the first lipidated answer. Systematic scanning identified lysine 26 as the attachment point; a C16 palmitic acid (a monoacid) was attached there through a γ-Glu linker, and lysine 34 was changed to arginine so the acylation would be single-site.^[3][11] The fatty acid gives albumin binding and partial protection from DPP-4, and the molecule also self-assembles into a seven-unit (heptamer) structure in the formulation that slows its absorption from the injection site. Together these extend the half-life to roughly 13 hours — enough for once-daily use.^[11][7]

Semaglutide pushed the same design further. The peptide was made more stable by replacing alanine 8 with Aib (2-aminoisobutyric acid), which blocks DPP-4 at the N-terminus; the linker was lengthened to γ-Glu plus two OEG spacers; and the fatty acid was upgraded to a C18 diacid. In the discovery work, a C18 diacid together with the γ-Glu-2×OEG linker gave the best combination of albumin affinity and retained receptor potency — about a 5.6-fold higher albumin affinity than liraglutide, and a half-life around a week (reported as roughly 46 hours in mini-pigs by one measure and about 165–168 hours in humans).^[2][3] That is what makes semaglutide a once-weekly molecule.

Tirzepatide, a dual GIP/GLP-1 receptor agonist, uses the same toolkit: a C20 fatty diacid attached at a lysine through a γ-Glu and two AEEA spacers, giving a half-life of roughly five days and a once-weekly interval.^[5][7] The progression C16 monoacid → C18 diacid → C20 diacid tracks neatly with once-daily → once-weekly duration.

The insulin parallel

Insulin designers reached the same idea independently. Insulin detemir attaches a C14 myristic acid to lysine B29 (with the terminal threonine removed) and relies on a mix of albumin binding and self-association for a longer, flatter basal profile. Insulin degludec uses a C16 fatty diacid joined through a γ-glutamyl spacer to lysine B29; after injection it assembles into long soluble multi-hexamer chains that slowly dissociate, creating a subcutaneous depot that releases insulin steadily for over 42 hours with no pronounced peak.^[12] Insulin icodec takes it to the once-weekly extreme with a C20 fatty diacid and very strong albumin binding, giving a mean half-life of about 196 hours.^[13] Across both the incretin and insulin families, the lesson is the same: chain length and the switch from monoacid to diacid are the dials that set duration.

Figures above are as reported in the cited sources and describe pharmacokinetic properties studied in animals and humans; they are illustrations of the chemistry, not instructions or outcomes for any subject.

Chain length, mono- versus diacid, and the potency trade-off

Lipidation is powerful but, like every half-life-extension strategy, it is a balance rather than a free gain. The central tension is between albumin affinity and receptor potency.

The fatty acid that recruits albumin is bulky and hydrophobic, and if it lies across the part of the peptide that binds its receptor it lowers measured potency in a binding or cell assay. Longer chains and diacids bind albumin harder but also tend to shade the active surface more, so pushing for maximum duration can cost activity.^[1][6] Designers manage the trade-off in three ways: they choose an attachment site away from the peptide’s active region; they insert hydrophilic spacers (the γ-Glu and OEG units) that hold the fatty acid out at arm’s length so it reaches albumin without draping over the peptide; and they accept a controlled loss of in-vitro potency when the vastly longer exposure in the body more than compensates — a molecule that is weaker per-molecule but present for a week can do more overall than a potent one gone in minutes.^[1][3]

This is why lipidation design reads as a screen rather than a formula. The GLP-1 discovery programmes tested families of fatty acids and linkers and chose the combination — C18 diacid with γ-Glu-2×OEG for semaglutide — that gave the highest albumin affinity while keeping receptor potency acceptable, and deliberately kept the peptide otherwise as close to the natural sequence as possible to limit the risk of an immune response.^[3] “Longer is better” is true only up to the point where solubility and potency start to fall off.

Lipidation, membranes and oral delivery

Albumin binding is the headline use of lipidation, but the fatty acid does something else worth noting: it makes the peptide more willing to interact with membranes. A hydrophobic tail gives a polar peptide a way to insert into a lipid bilayer, which is central to the natural membrane-anchoring forms and also matters for getting peptides across the gut.

Oral semaglutide is the clearest example. The same fatty-acid chain that binds albumin also acts as a membrane anchor: free-energy calculations find that inserting the lipid tail into a membrane is favourable, giving the otherwise poorly-absorbed peptide a foothold on the gut lining.^[14] That alone is not enough — oral semaglutide is co-formulated with a permeation enhancer, SNAC (sodium salcaprozate), which buffers the local stomach pH and transiently opens the lining so the peptide can cross — and even with both, oral bioavailability sits below about one percent.^[14][7] Lipidation is one contributor to oral peptide delivery, enabling but not sufficient on its own. The broader point is that a fatty acid changes how a peptide behaves at every lipid interface it meets, from the gut wall to albumin to its own tendency to cluster in solution.

How a lipidated peptide is characterised

Adding a fatty acid changes a peptide’s physical behaviour in ways that show up directly in the analytical laboratory, which is both how a lipidated peptide is confirmed and why it can be trickier to handle than its parent.

The most obvious change is hydrophobicity. On reversed-phase HPLC — the standard purity method, which separates molecules by how strongly they stick to a greasy column — a lipidated peptide is markedly more retained than the unmodified sequence, because the fatty acid grips the column. That shift is itself a fingerprint of successful acylation, and the method remains the primary way purity is measured. Identity is confirmed by mass spectrometry: the fatty acid and its linker add a precise, known mass, so the modified peptide appears at a predictably higher mass than the parent, and peptide mapping after digestion can confirm that the lipid is on the intended residue.^[1]

The fatty acid also makes the molecule surface-active — it behaves partly like a detergent. Above a certain concentration, lipidated peptides self-assemble into micelles, oligomers or, in some cases, larger ordered structures, exactly the behaviour that creates the useful injection-site depot but also something that has to be understood for formulation and for getting reproducible analysis.^[1] The same chains can promote aggregation, so handling and dissolution of a lipidated peptide can differ from a simple sequence. These behaviours are measured with the ordinary toolkit used to establish the identity and purity of any research peptide. Patriot Labs tests every batch of the peptides it sells by HPLC for purity and by mass spectrometry for identity through an independent US laboratory, with the certificate of analysis published on each product page; the general principles of reading those documents are covered in Understanding Peptide COA Testing.

What this guide does not establish

This guide explains a chemistry, not a use, and several boundaries are worth stating plainly.

• Nothing here describes how to use any peptide, lipidated or otherwise, in a person or animal. Half-life, albumin binding and clearance are described as measurable properties of molecules studied in laboratory and pharmacokinetic research, not as instructions or outcomes for any living subject.
• Approved-drug examples are historical and regulatory. Named products — liraglutide, semaglutide, tirzepatide and the acylated insulins — are cited to illustrate the chemistry of lipidation and its milestones, not to describe, compare or recommend any therapy.
• Specific figures are as reported in the cited sources. Half-life, albumin-affinity and chain-length numbers come from the reviews and studies referenced and are examples, not universal constants; the right design differs for every molecule.
• “Research grade” is not a therapeutic grade. A research compound that shares a name with an approved lipidated medicine is not that medicine and has not been made or tested to the same standard.
• Nothing here describes Patriot Labs’ supply chain beyond the testing facts stated above.

Frequently asked questions

What is lipidation?

Lipidation is the attachment of a lipid, most often a fatty acid, to a peptide or protein. In the body it is a natural modification that anchors proteins to membranes; in peptide drug design it is used deliberately to attach a fatty-acid chain so the peptide binds reversibly to albumin in the blood. Because albumin is large and long-lived, the bound peptide is filtered by the kidneys far more slowly and is shielded from enzymes, so it circulates much longer than the unmodified peptide.

What is the difference between lipidation and acylation?

The terms overlap. Lipidation is the general attachment of any lipid to a peptide or protein. Acylation, in this context, specifically means forming an amide bond between a fatty acid's carboxyl group and an amino group on the peptide, which is the most common way a fatty acid is added. Almost all lipidated peptide drugs are made by acylation, so in practice the words are often used interchangeably, but lipidation is the broader term that also covers prenylation, cholesterylation and other non-fatty-acid lipids.

How does a fatty acid make a peptide last longer in the blood?

The fatty acid binds non-covalently to serum albumin, the most abundant protein in blood. Albumin has several natural fatty-acid binding sites and a half-life of weeks because it is recycled rather than filtered out. When the peptide's fatty acid tail slots into one of those sites, the peptide travels bound to albumin most of the time. In that state it is too large to be filtered by the kidney, proteases reach it less easily, and only the small free fraction is active at any moment, so the overall circulating half-life rises from minutes to days.

Is semaglutide lipidated?

Yes. Semaglutide carries a C18 fatty diacid attached at lysine 26 through a gamma-glutamic acid and two short OEG spacer linker. That fatty acid binds albumin strongly, and together with an Aib substitution at position 8 that blocks the DPP-4 enzyme, it gives semaglutide a half-life of about a week, which is why it is studied as a once-weekly molecule. Tirzepatide uses a similar design with a longer C20 diacid, and liraglutide uses a shorter C16 palmitic acid for a roughly once-daily profile.

What is the gamma-glutamyl (gamma-Glu) linker?

The gamma-glutamyl linker is a small spacer, derived from the amino acid glutamic acid, placed between the peptide and the fatty acid. Because glutamic acid is joined through its side-chain (gamma) carboxyl rather than its main-chain alpha carboxyl, it adds length and a negative charge that holds the fatty acid away from the peptide surface. This improves albumin binding and solubility while keeping the peptide's active region accessible. Modern designs such as semaglutide add two OEG (mini-ethylene-glycol) units to the gamma-Glu for extra reach.

Does chain length matter in lipidation?

Yes, strongly. Longer and more hydrophobic fatty acids generally bind albumin more tightly and extend half-life further, which is why peptide drugs cluster around C14 to C20 chains. But longer is not automatically better: a chain that is too long or too bulky can bury the peptide's active surface and lower its measured potency, and it can make the molecule harder to dissolve. The optimal chain is screened for each peptide, balancing albumin affinity against retained receptor activity.

What is the difference between a fatty acid and a fatty diacid in these drugs?

A monoacid fatty acid has one carboxyl group, at the end that is not attached to the peptide, so that free end is a simple methyl tail; liraglutide's C16 palmitic acid is a monoacid. A fatty diacid has a carboxyl group at both ends, so the end that points away from the peptide carries a negative charge; semaglutide's C18 diacid and tirzepatide's C20 diacid are diacids. The terminal carboxyl of a diacid tends to anchor more firmly in albumin's fatty-acid pockets, which is one reason the once-weekly molecules use diacids.

What are the natural forms of protein lipidation?

In cell biology there are several. N-myristoylation attaches a C14 myristic acid to an N-terminal glycine; S-palmitoylation attaches a C16 palmitate to a cysteine through a reversible thioester bond; prenylation attaches a farnesyl (C15) or geranylgeranyl (C20) isoprenoid to a cysteine near the C-terminus; cholesterylation attaches cholesterol, famously to Hedgehog signalling proteins; and GPI anchors attach a complex glycolipid at the C-terminus. All of these mainly serve to tether a protein to a membrane or control its location, which is a different purpose from the albumin-binding use in drug design.

Does lipidation reduce a peptide's activity?

It can. The same fatty acid that recruits albumin can sit over the surface the peptide uses to bind its target, lowering measured potency in a binding or cell assay. The effect depends on where the fatty acid is attached and how long it is. Designers manage this by choosing an attachment site away from the active region, by inserting hydrophilic spacers such as gamma-Glu and OEG that hold the fatty acid away from the peptide, and by accepting a potency reduction when the far longer exposure more than makes up for it.

Can lipidation help a peptide be taken orally?

It contributes. A fatty-acid chain makes a peptide more membrane-interactive, which helps it engage the gut lining, and it is part of why oral semaglutide is feasible. But lipidation alone is not enough: oral semaglutide is co-formulated with a permeation enhancer called SNAC that transiently opens the stomach lining, and even so its oral bioavailability is below about one percent. Lipidation is one factor in oral peptide delivery, not a complete solution on its own.

References

1. Kurtzhals, P., Østergaard, S., Nishimura, E., & Kjeldsen, T. (2023). Derivatization with fatty acids in peptide and protein drug discovery. Nature Reviews Drug Discovery, 22(1), 59–80. doi:10.1038/s41573-022-00529-w
2. Lau, J., Bloch, P., Schäffer, L., et al. (2015). Discovery of the once-weekly glucagon-like peptide-1 (GLP-1) analogue semaglutide. Journal of Medicinal Chemistry, 58(18), 7370–7380. doi:10.1021/acs.jmedchem.5b00726
3. Knudsen, L. B., & Lau, J. (2019). The discovery and development of liraglutide and semaglutide. Frontiers in Endocrinology, 10, 155. doi:10.3389/fendo.2019.00155
4. Curry, S., Mandelkow, H., Brick, P., & Franks, N. (1998). Crystal structure of human serum albumin complexed with fatty acid reveals an asymmetric distribution of binding sites. Nature Structural Biology, 5(9), 827–835. PMID: 9731778. https://www.nature.com/articles/nsb0998_827
5. Ali, R., Sharma, A. V., & Chawla, P. A. (2022). Bumps and humps in the success of tirzepatide as the first GLP-1 and GIP receptor agonist. Health Sciences Review, 4, 100032. doi:10.1016/j.hsr.2022.100032
6. Madsen, K., et al. (2007). Structure–activity and protraction relationship of long-acting glucagon-like peptide-1 derivatives: importance of fatty acid length, polarity, and bulkiness. Journal of Medicinal Chemistry. doi:10.1021/jm070861j
7. Peri, R. V., Anchan, H., Jonnalagadda, K., Varghese, R., & Gupta, P. (2025). Designing GLP-1 delivery: structural perspectives and formulation approaches for optimized therapy. Nutrition & Diabetes, 15(1), 53. doi:10.1038/s41387-025-00397-4
8. Yuan, Y., Li, P., Li, J., Zhao, Q., Chang, Y., & He, X. (2024). Protein lipidation in health and disease: molecular basis, physiological function and pathological implication. Signal Transduction and Targeted Therapy, 9, 60. doi:10.1038/s41392-024-01759-7
9. Li, Y., Wang, Y., Wei, Q., Zheng, X., Tang, L., Kong, D., & Gong, M. (2015). Variant fatty acid-like molecules conjugation, novel approaches for extending the stability of therapeutic peptides. Scientific Reports, 5, 18039. doi:10.1038/srep18039
10. Colston, K. J., Faivre, K. T., & Schneebeli, S. T. (2025). Permeation enhancer-induced membrane defects assist the oral absorption of peptide drugs. Nature Communications, 16, 9512. doi:10.1038/s41467-025-64891-0
11. Glucagon-like peptide-1 — overview of native half-life and DPP-4 degradation. Wikipedia. https://en.wikipedia.org/wiki/Glucagon-like_peptide-1
12. Insulin degludec — structure, fatty-diacid acylation and multi-hexamer depot mechanism. Wikipedia. https://en.wikipedia.org/wiki/Insulin_degludec
13. Insulin icodec — C20 fatty-diacid acylation and once-weekly pharmacokinetics. Wikipedia. https://en.wikipedia.org/wiki/Insulin_icodec
14. Liraglutide — pharmacology overview (acylation, albumin binding, half-life). ScienceDirect Topics. https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/liraglutide
15. Peptide lipidation: a breakthrough strategy. Biopharma PEG (2023). https://www.biochempeg.com/article/377.html

For related reading, see Peptide Half-Life Extension for every route to a longer-lasting peptide, What Is PEGylation? for the synthetic-polymer alternative to a fatty acid, What Is DAC in Peptides? for a covalent albumin-binding approach, How Peptides Are Made for the synthesis behind the peptide before it is modified, and Understanding Peptide COA Testing for how identity and purity are shown.

All Patriot Labs products are sold strictly for in-vitro research and laboratory use only. Not for human or veterinary consumption. This guide is educational and describes the chemistry of lipidation in general terms; it is not medical advice, does not describe how to use any product, and makes no therapeutic claim about any compound.