Leuphasyl (Pentapeptide-18)_Dosage, benefits & legal status
Also known as pentapeptide-18, Leuphasyl, Tyr-D-Ala-Gly-Phe-Leu, D-Ala2 leucine-enkephalin
A topical peptide built from the body's own opioid, aimed at the nerve rather than the muscle.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Leuphasyl (Pentapeptide-18)?
Plain language first. The technical label stays, but it never stands alone.Overview
A topical peptide copied from one of the body's own painkiller molecules, used to quiet the nerve signal that creases skin. Weaker than an injection, and the sellers say so.
Pentapeptide-18 (Tyr-D-Ala-Gly-Phe-Leu), a topical enkephalin analog developed by Lipotec. Proposed mechanism is agonism at presynaptic opioid receptors, closing voltage-gated calcium channels and reducing acetylcholine exocytosis at the neuromuscular junction. Supporting data is in vitro and supplier-generated.
What it's used for
A topical peptide used to soften expression lines by reducing the nerve signal to small facial muscles.
How does Leuphasyl (Pentapeptide-18) work?
What it does in the body, and where.Leuphasyl is leucine-enkephalin with one amino acid swapped, and enkephalin is one of the body's own opioid signals.
- 01One substitution makes it last longerNatural leucine-enkephalin is Tyr-Gly-Gly-Phe-Leu. Leuphasyl replaces the glycine in position two with D-alanine, a mirror-image amino acid that enzymes are slower to cut.
- 02It acts on the nerve, not the muscleBinding an opioid receptor on the nerve ending is described as closing calcium channels, and without calcium entering, the nerve releases less acetylcholine. Vialox and SYN-AKE work at the other end of the same junction.
- 03Gentler than injection, and reversible by designSuppliers state plainly that it is weaker than botulinum toxin and preserves facial expression. That is an honest framing of a smaller effect.
Where this compound is thought to act.
What else is it used for?
Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
- Softening expression lines, applied to the skinSupplement or cosmetic
- Reducing acetylcholine release from the nerve endingEarly research
- Layered with Argireline, which suppliers report as additivenone
The published record
Papers and trials about Leuphasyl (Pentapeptide-18)
6 papers tagged human · 4 not reviews or lab · 0 clinical trial publications
Furthest stage reached: No clinical trial on record
Counted from Europe PMC indexing, not read by a person; a human tag can land on reviews, commentary or lab papers; clinical trial publications is the narrower count.
At a glance
Four things to know about Leuphasyl (Pentapeptide-18)
Evidence
Cosmetic
Category
Skin and cosmetic
Common vial
Varies
Half-life
Not measured, and not the right question
How much, and do you cycle it?
The range, and whether you take breaks.Serum, per product, daily. Not cycled Community practice
Used daily as part of a routine. The effect depends on continued use and returns to baseline when you stop, so there is nothing to cycle off.
Not measured, and not the right questionNo figure
This is a topical cosmetic ingredient. A blood half-life measures how fast something leaves the bloodstream, and these are not intended to reach it in meaningful amounts. What matters for a topical is how much penetrates the skin and how long it stays in the tissue, which is a different measurement and one that is rarely published.
You can compare this against the whole library to see where it sits.
What does it cost?
Typical dose and cost, in plain numbers.Leuphasyl (Pentapeptide-18) is not injected
It is taken on the skin (topical). Applied as a topical product at the concentration the manufacturer sets. There is no injected dose.
Leuphasyl (Pentapeptide-18) starts at $176.00 across 3 vendors, typically $1.08 per mg.
3 listings, last read Oct 10, 2026. Shipping and card fees are not included.
How do you store it?
Before mixing, and after.Room temperature, out of light. Cap it tight after each use.
Leuphasyl (Pentapeptide-18) ships as a cream, gel, or serum. Keep it at room temperature away from sun and heat unless the label says otherwise. Refrigerating an emulsion can split the texture. Watch for color, smell, or separation changes and stop using it if any appear.
What are the side effects and cautions?
Known cautions and warnings for this compound.Solubility, computed: 40% charged residues, 60% hydrophobic. Water usually sufficient.
A first-pass rule from peptide manufacturers' guidance. It does not account for disulfide bridges, salt form or how the powder was dried, and it predicts what should be easy rather than what will happen in your vial.
Who should avoid it
- A known allergy to this ingredient or to others in the same product
- Broken, cracked, or actively irritated skin
- Anyone who wants established safety data, because none exists for this compound in humans
Stop and get help
- A rash that spreads beyond where you applied it
- Swelling of the face, lips, or eyelids, or any trouble breathing
- Burning that does not settle after rinsing it off
- Anything unusual, since there is no known safety profile to compare it against
Common effects
- Reactions are not commonly reported, though no published testing has looked for them. Irritation from a product containing it may come from anything else in the formula.
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Leuphasyl (Pentapeptide-18) approved?
And where the numbers on this page come from.Not as a medicine. Leuphasyl (Pentapeptide-18) is sold without a prescription as a cosmetic ingredient, which is a different thing from being approved as a drug.
- Approval statusCosmeticSold without a prescription as an ingredient in cosmetics, such as skincare and hair products. The FDA does not approve cosmetics before they are sold, and being easy to buy says nothing about whether it works.
- RouteOn the skin (topical)
- Checked24 August 2026
- DoseFrom the concentration range manufacturers formulate at. This is a product strength, not a dose set by a regulator or a trial.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesNone traced yet.
What has happened recently
Regulated as a cosmetic ingredient, not a drug. Cosmetic ingredients are not reviewed for effectiveness before sale in the US, so a product may legally claim an appearance benefit without a trial behind it.
You can compare this against the whole library, or read how to check a seller.
What else is like Leuphasyl (Pentapeptide-18)?
Others in Skin and cosmetic, side by side.If you're weighing Leuphasyl (Pentapeptide-18), it's worth reading Lipopeptide, Nonapeptide-1 (Melanostatine-5), and Pal-AHK in the same class.
A topical peptide built from the body's own opioid, aimed at the nerve rather than the muscle.
- Dose
- Serum, per product
- How often
- Daily
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- Dose
- Topical serum, per product
- How often
- Daily
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- Dose
- Serum, per product
- How often
- Daily
A hair-peptide serum ingredient that borrows most of its reputation from GHK-Cu.
- Dose
- Topical serum, per product
- How often
- Daily
Guides for this compound
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
- How to Read a Peptide COA
What the purity number does and does not tell you, and how to spot an edited report.
- How to Vet a Peptide Vendor
Independent COAs, HPLC purity, and the red flags that mean walk away.
Sources
No primary source has been traced for this compound yet. Treat everything on this page as unverified until one is. How we grade evidence
Beyond these, 7 records are indexed. Browse the records